one hand, it raises fundamental doubts about the Davidsonian project, which seems to involve isolating specifically semantic knowledge from any other knowledge or skill in a way reflected by the ideal of homophony. Indexicality forces a departure from this ideal, and so from the aspiration of deriving the truth conditions of an arbitrary utterance on the basis simply of axioms which could hope to represent purely semantic knowledge. In defence of Davidson, I argue that once his original idea for (...) dealing with the familiar indexical expressions is suitably implemented, in terms of theorems expressing conditional truth-conditions, the contrast between semantic and nonsemantic knowledge occurs in an appropriate place: between knowledge of the conditional truth conditions themselves (semantic), and knowledge of their antecedents (non-semantic). For example, a simplified version of a conditional truth condition for an utterance u of “That is a cat” will say that for all x, if the utterer in uttering “that” in u thereby referred to x, u is true iff x is a cat. The conditional fact belongs to semantic knowledge; non-semantic knowledge is required to work out what the utterer referred to; the two kinds of knowledge conspire to enable a truth condition to be detached. The other kind of worry relates to difficult technical questions, relating to specific idioms, raised by context-dependence. I consider whether an argument by Travis (2006), designed to establish that there can be no correct truth conditional semantics, can be turned on its head, and used to establish a general method for bringing all forms of context-dependence within Davidsonʼs framework (using quantification into the qualifier “on understanding U”). I argue that this will not work, and that we are committed to a piecemeal examination of various cases, of which I give some examples. One of these relates directly to Travisʼs argument concerning the context-dependence of “grunt”. In addition, Davidsonians need to have a sharp eye for the distinction between pragmatic and semantic content, to be specified by a test akin to Griceʼs notion of cancelability; they should treat sentences like “Itʼs raining” by the conditional truth-condition method; and they should treat possessives as semantically very unspecific. It is part of the thesis of the paper that this list of examples by no means exhausts the cases a Davidsonian needs to address. (shrink)

This article provides a philosophical response to the need for truth-telling about colonial history, focussing on the Australian context. The response consists in inviting philosophers and the public to engage in social-justice practices specified by a model called Distributed Truth-Telling (DTT), which integrates the historiography of injustices affecting Indigenous peoples with insights from social philosophy and cultural evolution theory. By contrast to official and large-scale truth commissions, distributed truth-telling is a set of non-elitist practices that (...) weave three components: first, multisite, multiformat, and multiscale inquiries into injustices; second, remedial imaginings and reasoning about moral repair and reconciliated futures; and finally, emotions suitable for motivating agents to cooperatively plan and implement moral revolutions. Distributed truth-telling can entrench virtuous feedback loops that contribute to moral revolutions. However, vicious feedback loops associated with collective denial and biases can impair distributed truth- telling and thwart moral revolutions. (shrink)

In this paper, I argue that the cleavage between the theory of reference and the theory of meaning, which under the influence of Quine has dominated a large part of the philosophy of language of the last fifty years, is based on a misrepresentation of Tarski's achievement and on an overestimation of the scope and value of disquotation. In particular, I show that, if we accept Davidson's critique of disquotation, the same kind of reasons that Quine offered in opposition (...) to the Carnapian theory of meaning also apply, mutatis mutandis, to the Tarskian theory of reference. (shrink)

Most philosophers have largely downplayed any relevance of multiple meanings of the folk concept of truth in the empirical domain. However, confusions about what truth is have surged in political and everyday discourse. In order to resolve these confusions, we argue that we need a more accurate picture of how the term ‘true’ is in fact used. Our experimental studies reveal that the use of ‘true’ shows substantial variance within the empirical domain, indicating that ‘true’ is ambiguous between (...) a correspondence and a coherence reading. We then explore the consequences of these results for the project of re-engineering truth. (shrink)

Attention to the conversational role of alethic terms seems to dominate, and even sometimes exhaust, many contemporary analyses of the nature of truth. Yet, because truth plays a role in judgment and assertion regardless of whether alethic terms are expressly used, such analyses cannot be comprehensive or fully adequate. A more general analysis of the nature of truth is therefore required – one which continues to explain the significance of truth independently of the role alethic terms (...) play in discourse. We undertake such an analysis in this paper; in particular, we start with certain elements from Kant and Frege, and develop a construct of truth as a normative modality of cognitive acts (e.g., thought, judgment, assertion). Using the various biconditional T-schemas to sanction the general passage from assertions to (equivalent) assertions of truth, we then suggest that an illocutionary analysis of truth can contribute to its locutionary analysis as well, including the analysis of diverse constructions involving alethic terms that have been largely overlooked in the philosophical literature. Finally, we briefly indicate the importance of distinguishing between alethic and epistemic modalities. (shrink)

Despite some notable similarities between the scientific realisms of Sellars and Peirce (such as both being anti-representationalist, and future-directed), in his mature work Science and Metaphysics Sellars explicitly critiqued Peirce’s account of truth, as lacking “an intelligible foundation” (Sellars 1968: vii). In this paper, I explore Sellars’ proposed remedy to Peirce’s purported lack, in his complex and enigmatic account of picturing – a non-discursive ‘mapping’ of the world. I argue that although Sellars’ development of this idea is largely sound, (...) much of what he charges Peirce’s philosophy with missing is actually present there. By means of his semiotic icon / index / symbol distinction, Peirce manages to develop a philosophy of language which effectively coordinates the real order and the order of signification within the very structure of the proposition as he understands it, by contrast to Sellars’ claim that the two orders are merely connected by ‘analogy’. I also argue that in between Sellars’ ambitious account of veridicality, which appears to anticipate a form of scientific self-mensuration, and the dismissive ‘anti-truth’ quietism of neopragmatists such as Rorty, Peirce’s “contrite fallibilism” (Peirce CP 1.14) charts a wise middle path. (shrink)

A prevalent political narrative is that we are facing an epistemological crisis, where many citizens no longer care about truth and facts. Yet the view that we are living in a post-truth era relies on some implicit questionable empirical and normative assumptions. The post-truth rhetoric converts epistemic issues into motivational issues, treating people with whom we disagree as if they no longer believe in or care about truth. This narrative is also dubious on epistemic, moral, and (...) political grounds. It is epistemically dubious in being largely insensitive to the problem of complexity in politics; it is morally dubious because “post-truth” is often a derogatory label for individuals or groups that are deemed stupid, irrational, or morally compromised; and it is a politically toxic neologism because it purports to use the language of ‘truth’ as a weapon against power, yet these truth-claims are often themselves attempts to exert power over others by delegitimizing their perspectives. While it may seem as if truth and democracy are on especially bad terms lately, politics and truth have long had a vexed relationship, and moral panics about the value of truthfulness in politics are as old as politics itself. (shrink)

The essays collected in this volume are all concerned with the connection between fiction and truth. This question is of utmost importance to metaphysics, philosophy of language, philosophical logic and epistemology, raising in each of these areas and at their intersections a large number of issues related to creation, existence, reference, identity, modality, belief, assertion, imagination, pretense, etc. All these topics and many more are addressed in this collection, which brings together original essays written from various points of (...) view by philosophers of diverse trends. These essays constitute major contributions to the current debates that the connection between truth and fiction continually enlivens, and give a sense of the directions in which research on this question is heading. Contributors: Fred Adams, Frederick Kroon, Robert Howell, Brendan Murday, Terence Parsons, Graham Priest, Erich Rast, Manuel Rebuschi, Marion Renauld, R.M. Sainsbury, Grant Tavinor, Alberto Voltolini. (shrink)

In this paper I investigate how differences in approach to truth and logic (in particular, a deflationist vs. a substantivist approach to these fields) affect philosophers’ views concerning pluralism and normativity in these fields. My perspective on truth and logic is largely epistemic, focusing on the role of truth in knowledge (rather than on the use of the words “true” and “truth” in natural language), and my reference group includes Carnap (1934), Harman (1986), Horwich (1990), Wright (...) (1992), Beall and Restall (2006), Field (2009), Lynch (2009), and Sher (2016a).1 Whenever possible, I focus on positive rather than negative views on the issues involved, although in some cases this is not possible. (shrink)

Thomas Hofweber takes the semantic paradoxes to motivate a radical reconceptualization of logical validity, rejecting the idea that an inference rule is valid just in case every instance thereof is necessarily truth-preserving. Rather than this “strict validity”, we should identify validity with “generic validity”, where a rule is generically valid just in case its instances are truth preserving, and where this last sentence is a generic, like “Bears are dangerous”. While sympathetic to Hofweber’s view that strict validity should (...) be replaced by something allowing for exceptions, I argue that this should instead be truth-conduciveness, a matter of a large majority of instances being truth-preserving. The fact that inference rules have uncountably many instances, I argue, can be handled by defining truth-conduciveness as relative to finite sets of instances. Moreover, I argue that Hofweber’s position, while seemingly radical, may be less so under closer scrutiny. For the mere claim that classical rules and unrestricted truth rules are generically valid (or truth-conducive) is not in itself controversial. Also, if there is an answer to the question of which of these are also strictly valid, then the claim that generic validity is the central notion in logic is at most an interest-relative matter, since there is then also a fact of the matter as to which inference rules are (not) strictly valid. If no solution operating with strict validity to the paradoxes can be had, however, then the claim that validity should be identified with a weaker notion is better motivated. I argue that it is reasonable, in view of past failures, to conjecture that no ordinary solution will score high enough relative to standard (uncontroversial) desiderata to merit justified belief. Hence, it is unknowable which solution is correct. I further argue that this is best explained by its being metaphysically indeterminate which solution is correct. If this conjecture is true, then we ought instead to think of validity as allowing exceptions, and then take the “true logic” to be one that takes both the classical rules and the truth rules to be valid, i.e., truth-conducive. This logic scores very high on the desiderata on logics, and is therefore preferable to any logic operating with strict validity. (shrink)

One determining characteristic of contemporary sociopolitical systems is their power over increasingly large and diverse populations. This raises questions about power relations between heterogeneous individuals and increasingly dominant and homogenizing system objectives. This article crosses epistemic boundaries by integrating computer engineering and a historicalphilosophical approach making the general organization of individuals within large-scale systems and corresponding individual homogenization intelligible. From a versatile archeological-genealogical perspective, an analysis of computer and social architectures is conducted that reinterprets Foucault’s disciplines and political (...) anatomy to establish the notion of politics for a purely technical system. This permits an understanding of system organization as modern technology with application to technical and social systems alike. Connecting to Heidegger’s notions of the enframing (Gestell) and a more primal truth (anfänglicheren Wahrheit), the recognition of politics in differently developing systems then challenges the immutability of contemporary organization. Following this critique of modernity and within the conceptualization of system organization, Derrida’s democracy to come (à venir) is then reformulated more abstractly as organizations to come. Through the integration of the discussed concepts, the framework of Large-Scale Systems Composed of Homogeneous Individuals (LSSCHI) is proposed, problematizing the relationships between individuals, structure, activity, and power within large-scale systems. The LSSCHI framework highlights the conflict of homogenizing system-level objectives and individual heterogeneity, and outlines power relations and mechanisms of control shared across different social and technical systems. (shrink)

The Semitic myth of a savior/messiah has played a prominent metaphorical role in the socio-political history of the West. In the period of the Holy Roman Empire, the Christian God played the role of the Messiah. In the period of capitalist modernity, Reason played the same role, of course with the help of God, suitably reshaped by theology (the science of God). God and Reason conspired against Nature and the humans branded as pagans. This created innumerable problems and Fascism and (...) Communism emerged as reactions against that. After the defeat of fascism and the collapse of the Soviet model of Communism, there arose a new world order with the World Market as the new messiah. This paper posits that in each of these periods, the ethos has been largely dictated by the messiah and that the new messiah, World Market, has caused the rise of the new socio-cultural phenomenon, called post-truth. The emergence of Fascism in many parts of the world, including India, is mainly caused by the resultant widespread cynicism. Jacque Lacan’s ideas are substantially borrowed to develop the conceptual tools for the analysis. (shrink)

C. S. Peirce once defined pragmatism as the opinion that metaphysics is to be largely cleared up by the application of the following maxim for attaining clearness of apprehension: ‘Consider what effects that might conceivably have practical bearings we conceive the object of our conception to have. Then, our conception of these effects is the whole of our conception of the object.’ (Peirce 1982a: 48) More succinctly, Richard Rorty has described the position in this way.

Presence of users as the main actors of each adaptive reuse of a given cultural heritage site heavily depends on the quality of their sensual experience there. This, in turn, seems to stem from how much they trust the integrity and provenance of the heritage attributes and activities pending within such historical sites. This paper aims to define the sincerity and authenticity as influential indicators of the users’ trust in adaptive reuse of cultural heritage sites. To reach the goal, the (...) author hereof has analyzed all the industrial heritage sites in Iran which have been adaptively reused (case studies) and has surveyed 125 visitors. The findings confirm that sincerity and authenticity can largely influence the visitors’ trust and sensitize their experience. (shrink)

Let an iterated essentialist statement be a statement of the form 'It lies in the nature of x1,x2,... that it lies in the nature of y1,y2,... that φ'. Let Iteration be the thesis that there are true iterated essentialist statements. Iteration has recently been disputed by Dasgupta (2014) and Glazier (2017). Both authors take the falsity of Iteration to be central to the explanatory role of essentialist truths. An important consequence that is not explicitly noted by them is that the (...) falsity of Iteration would entail that metaphysical necessity is not reducible to essence in the manner suggested by Fine (1994). This paper defends Iteration against these challenges, drawing attention to some features of the collective essences of properties, propositions, and logical operations that have been largely neglected in discussions about essence. (shrink)

This paper concerns a distinction between circumstantial truths that hold because of the circumstances and acircumstantial truths that hold regardless of, or transcend, the circumstances. Previous discussions of the distinction tended to focus on its applications, such as to modality, logical truth, and essence. This paper focuses on developing the distinction largely, but not entirely, in abstraction from its potential applications. As such, the paper’s main contribution is to further clarify the distinction itself. An indirect contribution is to help (...) guide its future applications. (shrink)

This paper attempts to address the question what logical strength theories of truth have by considering such questions as: If you take a theory T and add a theory of truth to it, how strong is the resulting theory, as compared to T? Once the question has been properly formulated, the answer turns out to be about as elegant as one could want: Adding a theory of truth to a finitely axiomatized theory T is more or less (...) equivalent to a kind of abstract consistency statement. A large part of the interest of the paper lies in the way syntactic theories are 'disentangled' from object theories. (shrink)

Happy accidents happen even in philosophy. Sometimes our arguments yield insights despite missing their target, though when they do others can often spot it more easily. Consider the work of Donald Davidson. Few did more to explore connections among mind, language, and world. Now that we have critical distance from his views, however, we can see that Davidson’s accomplishments are not quite what they seem. First, while Davidson attacked the dualism of conceptual scheme and empirical content, he in fact illustrated (...) a way to hold it. Second, while Davidson used the principle of charity to argue against the dualism, his argument in effect treats the principle as constitutive of a conceptual scheme. And third, while Davidson asserted that he cannot define what truth ultimately is—and while I do not disagree—his work nonetheless allows us to saymore about truth than Davidson himself does. -/- I aim to establish these three claims. Doing so enriches our understanding of issues central to the history of philosophy concerning how, if at all, to divvy up the mental or linguistic contribution, and the worldly contribution, to knowledge. As we see below, Davidson was right in taking his work to be one stage of a dialectic begun by Immanuel Kant.1 He was just wrong about what that stage is. Reconsidering Davidson’s views also moves the current debate forward, as they reveal a previously unrecognized yet intuitive notion of truth—even if Davidson himself remained largely unaware of it. We begin however with scheme/content dualism and Davidson’s argument against it. (shrink)

Evolutionary anthropologists and archaeologists have been considerably successful in modelling the cumulative evolution of culture, of technological skills and knowledge in particular. Recently, one of these models has been introduced in the philosophy of science by De Cruz and De Smedt (Philos Stud 157:411–429, 2012), in an attempt to demonstrate that scientists may collectively come to hold more truth-approximating beliefs, despite the cognitive biases which they individually are known to be subject to. Here we identify a major shortcoming in (...) that attempt: De Cruz & De Smedt’s mathematical model makes one particularly strong tractability assumption that causes the model to largely miss its target (namely, truth accumulation in science), and that moreover conflicts with empirical observations. The second, more constructive part of the paper presents an alternative, agent-based model, which allows one to much better examine the conditions for scientific progress and decline. (shrink)

In spite of the intuitiveness of epistemic closure, there has been a stubborn stalemate regarding whether it is true, largely because some of the “Moorean” things we seem to know easily seem clearly to entail “heavyweight” philosophical things that we apparently cannot know easily—or perhaps even at all. In this paper, I will show that two widely accepted facts about what we do and don’t know—facts with which any minimally acceptable understanding of knowledge must comport—are jointly inconsistent with the (...) class='Hi'>truth of CLR. The proof works by supposing the truth of “Categorialism,” a thesis about the relation between basic categories and common nouns and predicates, which is itself a heavyweight claim that cannot be easily known to be either true or false. (shrink)

Ernst Jünger is known for his war writings, but is largely ignored by contemporary phenomenologists. In this essay, I explore his e Adventurous Heart which has recently been made available in English. is work consists of a set of fragments which, when related, disclose a coherent ow of philosophical thinking. Speci cally, I show that, beneath a highly poetic and obscure prose, Jünger posits how subjective experience and poetry allow individuals to realize truth. I relate parts of Jünger’s insights (...) to contributions by Husserl, Heidegger and Merleau-Ponty, arguing that Jünger o ers a unique and valuable contribution to the phenomenological discipline. (shrink)

A key assumption fuelling optimism about the progress of large language models (LLMs) in accurately and comprehensively modelling the world is that the truth is systematic: true statements about the world form a whole that is not just consistent, in that it contains no contradictions, but coherent, in that the truths are inferentially interlinked. This holds out the prospect that LLMs might in principle rely on that systematicity to fill in gaps and correct inaccuracies in the training data: (...) consistency and coherence promise to facilitate progress towards comprehensiveness in an LLM’s representation of the world. However, philosophers have identified compelling reasons to doubt that the truth is systematic across all domains of thought, arguing that in normative domains, in particular, the truth is largely asystematic. I argue that insofar as the truth in normative domains is asystematic, this renders it correspondingly harder for LLMs to make progress, because they cannot then leverage the systematicity of truth. And the less LLMs can rely on the systematicity of truth, the less we can rely on them to do our practical deliberation for us, because the very asystematicity of normative domains requires human agency to play a greater role in practical thought. (shrink)

In this paper we investigate if sentences presented as the result of the application of statistical models and artificial intelligence to large volumes of data – the so-called ‘Big Data’ – can be characterized as semantically true, or as quasi-true, or even if such sentences can only be characterized as probably quasi-false and, in a certain way, post-true; that is, if, in the context of Big Data, the representation of a data domain can be configured as a total structure, (...) or as a partial structure provided with a set of sentences assumed to be true, or if such representation cannot be configured as a partial structure provided with a set of sentences assumed to be true. (shrink)

Solar radiation management (SRM) may help to reduce the negative outcomes of climate change by minimising or reversing global warming. However, many express the worry that SRM may pose a moral hazard, i.e., that information about SRM may lead to a reduction in climate change mitigation efforts. In this paper, we report a large-scale preregistered, money-incentivised, online experiment with a representative US sample (N = 2284). We compare actual behaviour (donations to climate change charities and clicks on climate change (...) petition links) as well as stated preferences (support for a carbon tax and self-reported intentions to reduce emissions) between participants who receive information about SRM with two control groups (a salience control that includes information about climate change generally and a content control that includes information about a different topic). Behavioural choices are made with an earned real-money endowment, and stated preference responses are incentivised via the Bayesian Truth Serum. We fail to find a significant impact of receiving information about SRM and, based on equivalence tests, we provide evidence in favour of the absence of a meaningfully large effect. Our results thus provide evidence for the claim that there is no detectable moral hazard with respect to SRM. [Open access]. (shrink)

This article arises indirectly out of the development of a particular approach, called ATT-Meta, to the understanding of some types of metaphorical utterance. However, the specifics of the approach are not the focus of the present article, which concentrates on some general issues that have informed, or arisen from, the development of the approach. The article connects those issues to the questions of metaphorical meaning and truth. -/- A large part of the exploration of metaphor in fields such (...) as Cognitive Linguistics and natural language Pragmatics takes metaphor to rest on complex mappings between a target subject matter and a source subject matter (see, e.g., Lakoff 1993, 2008). This is one main way in which some aspects of the source, generally including some structural aspects, can have parallels in the target. It is typical for much, and perhaps the whole, of the meaning of a metaphorical expression to be explained by means of these parallels. We will talk about “parallelism” rather than “isomorphism,” or even “analogy,” because “isomorphism” implies a strict one-to-one correspondence between items in the source scenario and items in the target scenario, and analogy theorists often hold that analogy rests on isomorphism. We wish not to prejudge the question of whether looser, messier forms of parallelism are sometimes needed. Also, we will talk about parallels rather than mappings, because our discussion will embrace the question of parallelism that may be discernible, albeit implicitly, in accounts of metaphor that are not presented as being based on mappings. Three main cases of such accounts are Relevance Theory (RT: e.g., Sperber & Wilson 2008, Wilson & Carston 2006), the categorization-based or "class-inclusion“ approach (Glucksberg 2008), and Ritchie’s (2006) CLST account (Context-Limited Simulation Theory). -/- One main issue we will address is that of substantial non-parallelism that can exist between source and target subject-matters in metaphor: more precisely, the issue that there may be source aspects that are exploited by the utterance and have a deep effect on metaphorical interpretation but that do not themselves have a natural parallel in the target subject-matter (although we will point out that artificial parallels can generally be created). This is part of a broader point that the content of metaphorical discourse should often be seen as being derived in a rather holistic way from several metaphorical bits of the discourse, which conspire to describe some source-domain scenario, rather than being derived by putting together metaphorical meanings of each metaphorical bit (even if each bit could in principle be assigned its own separate metaphorical meaning). As a result, we suggest that it is misguided to think of the propositions making up the content (or, if you like, "meaning“) about the target scenario that is being described is a matter of metaphorical meaning of specific grammatical units such as sentences, clauses or other constituents that a traditional semantic theory would assign propositional meaning to. Rather, grammatical units (that are to be taken metaphorically) have meanings in source-domain terms; content in target-domain terms is derived from the source-domain scenario depicted by those units and fleshed out through inference; and the target-domain content is only (in general) fuzzily relatable to particular grammatical units. This view is on a spectrum at whose extreme point we could place Davidson’s (1984) view that metaphors only have literal (i.e., source-domain) meanings, with other effects on the understander not being a matter of propositional content. However, on our view it is proper to take metaphorical discourse as having non-literal meaning, couched as a collection of propositions, among other things possibly; it is just that the propositions are not to be thought of (in general) as meaning of specific sentences, clauses or other grammatical units rather than of a possibly only fuzzily delineated piece of discourse. -/- A second main concern of the article is the question of how much, and what types of, inference are involved in the derivation of metaphorical meaning. While our own ATT-Meta approach accords with, amongst other accounts, Relevance Theory (RT) as to the centrality of inference in metaphor interpretation, we disagree with RT on its claim that metaphor interpretation is a matter of (a relatively high degree of) concept "broadening“ and (often) "narrowing“. We argue that almost all inference can in fact be theoretically re-described as concept broadening and/or narrowing, and what is left over should be included in the metaphor interpretation process anyway. Thus, the RT claim about broadening and narrowing really just says that inference, of unrestricted type, is involved in metaphor understanding, in accord with what ATT-Meta claims. (shrink)

I provide in this paper an examination of the influence of Immanuel Kant on the internal realist Hilary Putnam. I begin by discussing Putnam’s transition from external, or metaphysical, realism to internal realism, and argue in favor of the view that Kant is best understood as an internal realist. Where Putnam is concerned, I am interested here only in his versions of external and internal realism and not with his more recent views. Having laid out a case for internal realism, (...) I go on to discuss and defend Putnam’s interpretation of Kant’s views on the nature of truth, arguing that although Kant accepts correspondence as a nominal definition of truth, he should not be understood as endorsing the metaphysical realist conception of truth. I conclude by arguing against those, including Ian Hacking and Allen Wood, who believe that the internal realist Putnam misinterpreted Kant on the nature of truth. This criticism rests on a misunderstanding of what Kant must have meant by ‘correspondence.’ Kant does not offer a theory of truth, but had he done so, his theory would be compatible with the internal realist Putnam’s. The view that their views on the nature of truth are incompatible is founded largely on misunderstanding of Kant, Putnam or both. (shrink)

In his 1925/26 lecture Logic: The Question of Truth Heidegger turns to an interpretation of the Critique of Pure Reason in order to elucidate his own understanding of time. The largely overlooked lecture series, I argue, is at the root of Heidegger’s exposition of the concept of time and its relationship with human existence (Dasein). Although Heidegger claims that Kant’s concept of time is confined to that of ‘world-time,’ Heidegger develops the first exposition of his understanding of time as (...) ur-temporality via critical analysis of the Critique of Pure Reason. The investigation reveals the conceptual context behind the relationship between time and Dasein, which develops out of Heidegger’s first in-depth interpretation of the Critique of Pure Reason. (shrink)

I am very used to strange books and special people but Hawkins stands out due to his use of a simple technique for testing muscle tension as a key to the “truth” of any kind of statement whatsoever—i.e., not just to whether the person being tested believes it, but whether it is really true! What is well known is that people will show automatic, unconscious physiological and psychological responses to just about anything they are exposed to—images, sounds, touch, odors, (...) ideas, people. So muscle reading to find out their true feelings is not radical at all, unlike using it as a dousing stick (more muscle reading) to do “paranormal science”. Hawkins describes the use of decreasing tension in the muscles of an arm in response to increases in cognitive load thus causing the arm to drop in response to the constant pressure of someone’s fingers. He seems unaware that there is a long established and vast ongoing research effort in social psychology referred to by such phrases as ‘implicit cognition’, ‘automaticity’ etc., and that his use of ‘kinesiology’ is one tiny section. In addition to muscle tone (infrequently used) social psychologists measure EEG, galvanic skin response and most frequently verbal responses to words, sentences, images or situations at times varying from seconds to months after the stimulus. Many, such as Bargh and Wegner, take the results to mean we are automatons who learn and act largely without awareness via S1 and many others such as Kihlstrom and Shanks say these studies are flawed and we are creatures of S2. Though Hawkins seems to have no idea, as in other areas of the descriptive psychology of higher order thought, the situation regarding “automaticity” is still as chaotic as it was when Wittgenstein described the reasons for the sterility and barrenness of psychology in the 30’s. Nevertheless, this book is an easy read and some therapists and spiritual teachers may find it of use. -/- Those wishing a comprehensive up to date framework for human behavior from the modern two systems view may consult my article The Logical Structure of Philosophy, Psychology, Mind and Language as Revealed in Wittgenstein and Searle 59p(2016). For all my articles on Wittgenstein and Searle see my e-book ‘The Logical Structure of Philosophy, Psychology, Mind and Language in Wittgenstein and Searle 367p (2016). Those interested in all my writings in their most recent versions may consult my e-book Philosophy, Human Nature and the Collapse of Civilization - Articles and Reviews 2006-2016 662p (2016). -/- All of my papers and books have now been published in revised versions both in ebooks and in printed books. -/- Talking Monkeys: Philosophy, Psychology, Science, Religion and Politics on a Doomed Planet - Articles and Reviews 2006-2017 (2017) Amazon ASIN # B071HVC7YP. -/- The Logical Structure of Philosophy, Psychology, Mind and Language in Ludwig Wittgenstein and John Searle--Articles and Reviews 2006-2016 (2017) Amazon ASIN # B071P1RP1B. -/- Suicidal Utopian Delusions in the 21st century: Philosophy, Human Nature and the Collapse of Civilization - Articles and Reviews 2006-2017 (2017) Amazon ASIN # B0711R5LGX . (shrink)

I am very used to strange books and special people, but Hawkins stands out due to his use of a simple technique for testing muscle tension as a key to the “truth” of any kind of statement whatsoever—i.e., not just to whether the person being tested believes it, but whether it is really true! What is well known is that people will show automatic, unconscious physiological and psychological responses to just about anything they are exposed to—images, sounds, touch, odors, (...) ideas, people. So, muscle reading to find out their true feelings is not radical at all, unlike using it as a dousing stick (more muscle reading) to do “paranormal science”. -/- Hawkins describes the use of decreasing tension in the muscles of an arm in response to increases in cognitive load thus causing the arm to drop in response to the constant pressure of someone’s fingers. He seems unaware that there is a long established and vast ongoing research effort in social psychology referred to by such phrases as ‘implicit cognition’, ‘automaticity’ etc., and that his use of ‘kinesiology’ is one tiny section. In addition to muscle tone (infrequently used) social psychologists measure EEG, galvanic skin response and most frequently verbal responses to words, sentences, images or situations at times varying from seconds to months after the stimulus. Many, such as Bargh and Wegner, take the results to mean we are automatons who learn and act largely without awareness via S1 (automated System 1) and many others such as Kihlstrom and Shanks say these studies are flawed and we are creatures of S2 (deliberative System 2). Though Hawkins seems to have no idea, as in other areas of the descriptive psychology of higher order thought, the situation regarding “automaticity” is still as chaotic as it was when Wittgenstein described the reasons for the sterility and barrenness of psychology in the 30’s. Nevertheless, this book is an easy read and some therapists and spiritual teachers may find it of use. -/- Those wishing a comprehensive up to date framework for human behavior from the modern two systems view may consult my book ‘The Logical Structure of Philosophy, Psychology, Mind and Language in Ludwig Wittgenstein and John Searle’ 2nd ed (2019). Those interested in more of my writings may see ‘Talking Monkeys--Philosophy, Psychology, Science, Religion and Politics on a Doomed Planet--Articles and Reviews 2006-2019 3rd ed (2019), The Logical Structure of Human Behavior (2019), and Suicidal Utopian Delusions in the 21st Century 4th ed (2019) . (shrink)

Scientific realists argue that present theories are more successful than past theories, so present theories will not be superseded by alternatives, even though past theories were superseded by alternatives. Alai (2016) objects that although present theories are more successful than past theories, they will be replaced by future theories, just as past theories were replaced by present theories. He contends, however, that past theories were partly true, and that present theories are largely true. I argue that Alai’s discrimination between past (...) and present theories is subject to his own criticism against realists’ discriminations between past and present theories, and also subject to other criticisms that philosophers have raised against scientific realism and pessimism. (shrink)

Quine's aim in this slim book is to "update, sum up and clarify variously intersecting views on cognitive meaning, objective referencce, and the grounds of knowledge." Only nine pages had previously appeared as the book came to print. It is based largely on unpublished lectures and informal discussions of the past ten years back to the Immanuel Kant Lectures given at Stanford in 1980. It does not, then duplicate Leonelli's Italian translation of the Kant lectures, La Scienza E I Datti (...) di Senso, which appeared in 1987. (shrink)

Truth by convention, once thought to be the foundation of a uniquely promising approach to explaining our access to the truth in nonempirical domains, is nowadays widely considered an absurdity. Its fall from grace has been due largely to the influence of an argument that can be sketched as follows: our linguistic conventions have the power to make it the case that a sentence expresses a particular proposition, but they can’t by themselves generate truth; whether a given (...) proposition is true—and so whether the sentence that expresses it is true—is a matter of what the world is like, which means it isn’t a matter of convention alone. The consensus is that this argument is decisive against truth by convention. Strikingly, though, it has rarely been formulated with much precision. Here I provide a new rendering of the argument, one that reveals its structure and makes transparent just what assumptions it requires, and then I assess conventionalists’ prospects for resisting each of those assumptions. I conclude that the consensus is mistaken: contrary to what is almost universally thought, there remains a promising way forward for the conventionalist project. Along the way, I clarify conventionalists’ commitments by thinking about what truth by convention would need to be like in order for conventionalism to do the epistemological work it’s intended to do. (shrink)

Largely thanks to Mill’s influence, the suggestion that the state ought to restrict the distribution of misinformation will strike most philosophers as implausible. Two of Mill’s influential assumptions are particularly relevant here: first, that free speech debates should focus on moral considerations such as the harm that certain forms of expression might cause; second, that false information causes minimal harm due to the fact that human beings are psychologically well equipped to distinguish truth and falsehood. However, in addition to (...) our moral obligations, we also have a distinct set of epistemic obligations—and even when a false belief doesn’t harm anyone, it constitutes an epistemically bad outcome. Moreover, Mill was profoundly mistaken about human psychology: human beings are vulnerable to the influence of a wide variety of false claims via a wide variety of psychological mechanisms. Consequently, there is a purely epistemic justification for restricting the distribution of misinformation: because each of us has an individual epistemic obligation to avoid unnecessary exposure to misinformation, and because avoiding such exposure is simply too difficult when acting alone, we all have a shared epistemic obligation to establish laws or regulations restricting the widespread distribution of misinformation. (shrink)

In this paper I address issues related to the problem of future contingents and the metaphysical doctrine of fatalism. Two classical responses to the problem of future contingents are the third truth value view and the all-false view. According to the former, future contingents take a third truth value which goes beyond truth and falsity. According to the latter, they are all false. I here illustrate and discuss two ways to respectively argue for those two views. Both (...) ways are similar in spirit and intimately connected with fatalism, in the sense that they engage with the doctrine of fatalism and accept a large part of a standard fatalistic machinery. (shrink)

This chapter from Michel Serres’s comprehensive study on Leibniz—"The System of Leibniz and its Mathematical Models [Le système de Leibniz et ses modèles mathématiques]"—examines Leibniz’s epistemological framework. This framework, which Leibniz developed for a large part in his “Meditations on Knowledge, Truth, and Ideas [Meditationes de cognitione, veritate et ideis],” is pitched against Descartes’s "Meditations on First Philosophy [Meditationes de Prima Philosophia]" and the method of systematic doubt developed therein. While Descartes rejects any knowledge with the slightest possibility (...) of falsehood, Leibniz accepts knowledge with even a minimal degree of truth. Leibniz’s approach involves a progressive genesis of truth through a series of filters, each further refining knowledge. This process is intrinsically linked to infinitism and combinatorics, allowing for a gradual differentiation of the distinct from the indistinct. The filters are applied sequentially, with each filter proceeding through its own oppositions, resulting in a spectrum of knowledge ranging from obscure to clear, confused to distinct, inadequate to adequate, and symbolic to intuitive. This framework facilitates pluralism within rationalism that proceeds through evolving or regional truths. The filters overlap, and only the final stage of knowledge is devoid of mixture. Leibniz’s epistemology is non-Cartesian, as it relativizes truth and falsehood at each stage of the filtering process. It also accounts for the limitations of sensory perception, attributing them to the imperfection of the human mind in its current state. (Translated by Martijn Boven). (shrink)

It has been largely assumed from the start that truth, the first premise of the Tripartite theory of Knowledge, is necessary for a mental state of knowing. And this has intuitively made sense. Examples that demonstrate the logic of this premise are wide-spread and easily found. Yet, if one tries to establish the necessity of this condition for oneself, one may discover, a logical flaw in this premise. In theory truth is necessary, however, in practice it is not (...) truth that establishes knowledge. -/- We obtain knowledge using our perception or five senses. We accept the subjectivity of perspective, even though truth may or may not be established. We reject knowledge only when evidence of falsehood is obtained, if ever. -/- In practice, in the obtaining of knowledge of the conditional, those things we experience that could have been otherwise, truth is not established. The fundamental application of how we attain knowledge is in witnessing with our perception, our five senses, evidence for our conclusion. However, evidence provides support for our conclusion, by way of justification, but does not by itself provide truth. And therefore, it is not truth that is necessary for knowledge. It is the lack of evidence of falsehood in our conclusion that is the basis of our knowledge. And a lack of evidence of falsehood, is not the equal of truth. -/- The following thought experiment will demonstrate this flaw between theory and practice. (shrink)

Early artificial intelligence research was dominated by intellectualist assumptions, producing explicit representation of facts and rules in “good old-fashioned AI”. After this approach foundered, emphasis shifted to deep learning in neural networks, leading to the creation of Large Language Models which have shown remarkable capacity to automatically generate intelligible texts. This new phase of AI is already producing profound social consequences which invite philosophical reflection. This paper argues that Charles Peirce’s philosophy throws valuable light on genAI’s capabilities first with (...) regard to meaning, then knowledge and truth. Firstly, I explore how Peirce’s icon/index/symbol distinction illuminates the functioning of genAI. I argue that genAI’s engineers have skilfully captured a form of symbolicity, but no other sign-kind. In lacking indexical signs, LLMs lack connection with, and accountability to, particular worldly objects. In lacking iconic signs, LLMs are insufficiently disciplined by structural – most notably logical – relationships. Then I argue that GenAI’s astounding stream of articulate, truth-semblant, yet worthless texts issues a timely reckoning to modern philosophy’s representational realism. By contrast, Peirce’s pragmatism scaffolds a rich relational realism (Gili and Maddalena 2022), which shows how meaningful concepts, and a grasp of truth, can only occur across multiple cognitive systems who are simultaneously richly related with one another, and a shared environment in which they continually act and receive feedback, within a logical space of reasons. As Peirce himself noted, “Mere knowledge, though it be systematized, may be a dead memory; while by science we all habitually mean a living and growing body of truth”. (shrink)

Is logic empirical? Is logic to be found in the world? Or is logic rather a convention, a product of conventions, part of the many rules that regulate the language game? Answers fall in either camp. We like the linguistic answer. In this paper, we want to analyze how a linguistic community would tackle the problem of developing a logic and show how the linguistic conventions adopted by the community determine the properties of the local logic. Then show how to (...) move from a notion of logic that varies from community to community to a notion of logic that is in a sense universal. The framework is conventional up to a point: we have sentences, atomic and composite, the connectives are interpreted, values are computed, and the value of a composite sentence is a function of the values of its subsentences. Less conventional is the use of a plurality of truth values, and the sharp distinction we draw between sentences and statements, in the spirit of the distinction between proposition and judgment that one may find in proof theory. The linguistic community will face many choices. What are the good ones, the ones to avoid? Are there, in some sense, optimal choices? These are the kind of issues we are addressing. Where do we end up? With some kind of universal bivalent logic, ironically enough. We start from an arbitrarily large number of truth values, atomic sentences and connectives, construct a generic many-valued logic, recover more or less the usual results and issues, and in the end it all comes down to a positive bivalent logic with two connectives, `and' and `or', as if logic is nothing more than a mere accounting of possibilities. (shrink)

A large part of Richard Rorty’s works focus on criticizing the received view about philosophy. He argues, in his historical reconstruction of philosophical activity, that there has always been a misconception about philosophy in the history of philosophy. This misconception assumes that philosophy aims to grasp the ultimate knowledge, so it desperately engages in an attempt to achieve “truth”. In this view, which he calls representationalism and points to it by the metaphor of the mirror of nature, knowledge (...) aims to represent something out of mind, and the duty of philosophy is to put forward a theory about the representation. According to Rorty, based on this popular view philosophy is a foundational discipline that aims to evaluate epistemological claims of other disciplines. Rorty attempts to criticize and reject this Cartesian epistemological agenda for philosophy. Rorty’s approach to philosophy is therapeutic; that is, he tries to resolve philosophical problems rather than solve them. By adopting a historical method, Rorty seeks to show that “philosophy as epistemology” is a result of the dominance of what he calls the metaphor of the mirror of nature. From a critical rationalist perspective, the present article intends to critique Rorty’s views on epistemology. In this paper, Rorty’s historiographical approach is criticized in several ways. First, Rorty offers a one-sided and biased reconstruction of the history of philosophy to fit the abovementioned metaphor. Secondly, he treats history as rigid data from which it is possible to draw doctrinal conclusions. Whereas, as critical rationalists have said time and again, history by itself has no meaning. Moreover, Rorty’s justificationism is criticized. Rorty maintains that knowledge needs to be justified, and since it cannot be justified through representation, it must be justified by the consent of society. In other words, agreement in a group of people can provide an epistemic authority. Thus, both Rorty’s view and foundationalism, despite their differences, share justificationism in epistemology. That is, they both believe that knowledge needs to be justified. On the other hand, as critical rationalists have shown, justification in any shape and form, whether internal or external, is neither possible nor necessary. We also attempt to illustrate how Rorty’s epistemological approach results in confusion between epistemology and psychology; moreover, his epistemological behaviorism still suffers from some sort of justifications. In conclusion, Rorty expresses his criticism of epistemology with the metaphor of the mirror of nature. According to him, foundationalism is the result of the conflation of the Platonic conception of knowledge as something unchangeable, with the Cartesian mind that seeks certainty. However, his ignorance of the main crux of the matter in epistemology causes his own suggestion of epistemological behaviorism to suffer from the same problem, that is justificationism, which now appears in another form, i.e., social consensus. While, as critical rationalists repeated time and again, justification is neither possible nor necessary and not even desirable. They have shown that a non-justificationist approach to knowledge aimed at truth as a regulative idea could be a better approach. (shrink)

This paper articulates and defends a conception of logical form as semantic form revealed by a compositional meaning theory. On this conception, the logical form of a sentence is determined by the semantic types of its primitive terms and their mode of combination as it relates to determining under what conditions it is true. We develop this idea in the framework of truth-theoretic semantics. We argue that the semantic form of a declarative sentence in a language L is revealed (...) by a (canonical) proof of its T- sentence in an interpretive truth theory for L. We give a precise characterization of sameness of logical form between any two declarative sentences in any two languages in terms of the notion of corresponding proofs in interpretive truth theories for the languages. We illustrate the utility of this approach with a number of examples. We then extend the characterization to non-declaratives in a generalization of truth-theoretic semantics that appeals to fulfillment conditions, of which truth conditions are one variety. On this approach, logical forms are not reified, and the notion of sameness of logical form is treated as conceptually basic. We discuss the relation of this conception of logical form to the project of identifying logical constants, reviewing two approaches, one of which takes topic neutrality as central, the other recursion. We argue that the project of identifying logical constants for the purposes of classifying together valid arguments is largely independent of that identifying logical form of sentences, and urge an ecumenical approach to extending talk of logical constants beyond where it is currently well-grounded. (shrink)

The idea that science is objective, or able to achieve objectivity, is in large part responsible for the role that science plays within society. But what is objectivity? The idea of objectivity is ambiguous. This paper distinguishes between three basic forms of objectivity. The first form of objectivity is ontological objectivity: the world as it is in itself does not depend upon what we think about it; it is independent of human thought, language, conceptual activity or experience. The second (...) form of objectivity is the objectivity of truth: truth does not depend upon what we believe or justifiably believe; truth depends upon the way reality itself is. The third form of objectivity is epistemic objectivity: this form of objectivity resides in the scientific method which ensures that subjective factors are excluded, and only epistemically relevant factors play a role in scientific inquiry. The paper considers two problems that arise for the notion of epistemic objectivity: the theory-dependence of observation and the variability of the methods of science. It is argued that the use of shared standard procedures ensures the objectivity of observation despite theory-dependence. It is argued that the variability of methods need not lead to epistemic relativism about science. The paper concludes with the realist suggestion that the best explanation of the success of the sciences is that the methods employed in the sciences are highly reliable truth-conducive tools of inquiry. The objectivity of the methods of the sciences leads to the objective truth about the objective world. (shrink)

Evaluating large language models (LLMs) for tasks like fact extraction in support of knowledge graph construction frequently involves computing accuracy metrics using a ground truth benchmark based on a knowledge graph (KG). These evaluations assume that errors represent factual disagreements. However, human discourse frequently features metalinguistic disagreement, where agents differ not on facts but on the meaning of the language used to express them. Given the complexity of natural language processing and generation using LLMs, we ask: do metalinguistic (...) disagreements occur between LLMs and KGs? Based on an investigation using the T-REx knowledge alignment dataset, we hypothesize that metalinguistic disagreement does in fact occur between LLMs and KGs, with potential relevance for the practice of knowledge graph engineering. We propose a benchmark for evaluating the detection of factual and metalinguistic disagreements between LLMs and KGs. An initial proof of concept of such a benchmark is available on Github. (shrink)

Fictionalism plays a significant role in philosophy today, with defenses spanning mathematics, morality, ordinary objects, truth, modality, and more.1 Fictionalism in the philosophy of science is also gaining attention, due in particular to the revival of Hans Vaihinger’s work from the early twentieth century and to heightened interest in idealization in scientific practice.2 Vaihinger maintains that there is a ubiquity of fictions in science and, among other things, argues that Nietzsche supports the position. Yet, while contemporary commentators have focused (...) on fictionalism in Nietzsche’s moral philosophy, his view of fictions in science has remained largely unexamined.3 In this article, I begin... (shrink)

With his influence on the development of physiology, physics and geometry, Hermann von Helmholtz – like few scientists of the second half of the 19th century – is representative of the research in natural science in Germany. The development of his understanding of science is not less representative. Until the late sixties, he emphatically claimed the truth of science; later on, he began to see the conditions for the validity of scientific knowledge in relative terms, and this can, in (...) summary, be referred to as hypothesizing. Already in the past century, HeImholtz made first approaches to an understanding of science, which were incompatible with his own former position and which pointed to the modern age to an astonishingly large extent. A comparison with Karl R. Popper's logic of research will illustrate how closely he nevertheless approached modern understanding of science. In Popper's logic of research, hypothesizing of scientific knowledge is definitely much more advanced than in Helmholtz's theory of science. What begins vaguely to emerge with Helmholtz has already become an explicitly formulated programme with Popper. Although HeImholtz and Popper are not on a direct line of epistemological development and Popper refers to HeImholtz only rarely and casually, there are in fact surprising points of contact which have not been taken notice of so far and which appear above all if one looks at Helmholtz's understanding of science against the background of Popper's logic of research. (shrink)

Philosophers and social scientists largely agree that fake news is not just necessarily untruthful, but necessarily insincere: it’s produced either with the intention to deceive or an indifference toward its truth. Against this, I argue insincerity is neither a necessary nor obviously typical feature of fake news. The main argument proceeds in two stages. The first, methodological step develops classification criteria for identifying instances of fake news. By attending to expressed theoretical and practical interests, I observe how our classification (...) practices turn on worries about fake news’s unique political-epistemic risks. From this, I argue (i) theories of fake news should capture independent mechanisms that realise these risks and (ii) the manifestation of them suffices for classifying a news story as fake news. The second step applies the classification criteria to bad science journalism. I argue the systematic epistemic faults in bad science journalism manifest the same political-epistemic risks we see in fake news, which suffices to justify classifying it as fake news. But since such faults aren’t plausibly attributed to its propagators being insincere, insincerity doesn’t function independently as a mechanism for realising fake news’s political-epistemic risks. Thus, I conclude, we should exclude insincerity from our accounts of the phenomenon. (shrink)

In this article, I define a cultural epistemology as a set of socially reinforced assumptions about how knowledge and truth are produced. Unlike a philosophical epistemology, a cultural epistemology is largely the product of culture and largely invisible. As products of culture, cultural epistemology are relatively unquestioned and, in many cases, philosophically unsophisticated. There are three common types of cultural epistemologies, influenced by who holds power in a given society: an epistemological monarchy, an epistemological oligarchy and an epistemological democracy. (...) A given cultural epistemology subsequently influences the legitimacy of culture and government itself. I argue argue that Americans tend to hold an "epistemological democracy" with two distinct facets: a trust in consensus, linked to living in a democratic republic, and a trust in their own self-interest, linked to market economics and capitalism more generally. These two facets combine, interact, and even oppose each other to legitimize and challenge American culture and its political and economic systems. (shrink)

It has been known for some time that context-dependence poses a problem for disquotationalism, but the problem has largely been regarded as one of detail: one that will be solved by the right sort of cleverness. I argue here that the problem is one of principle and that extant solutions, which are based upon the notion of translation, cannot succeed.

This essay presents arguments for the claim that in the best of all possible worlds (Leibniz) there are sources of unpredictability and creativity for us humans, even given a pancomputational stance. A suggested answer to Chaitin’s questions: “Where do new mathematical and biological ideas come from? How do they emerge?” is that they come from the world and emerge from basic physical (computational) laws. For humans as a tiny subset of the universe, a part of the new ideas comes as (...) the result of the re-configuration and reshaping of already existing elements and another part comes from the outside as a consequence of openness and interactivity of the system. For the universe at large it is randomness that is the source of unpredictability on the fundamental level. In order to be able to completely predict the Universe-computer we would need the Universe-computer itself to compute its next state; as Chaitin already demonstrated there are incompressible truths which means truths that cannot be computed by any other computer but the universe itself. (shrink)

Girolamo Saccheri (1667--1733) was an Italian Jesuit priest, scholastic philosopher, and mathematician. He earned a permanent place in the history of mathematics by discovering and rigorously deducing an elaborate chain of consequences of an axiom-set for what is now known as hyperbolic (or Lobachevskian) plane geometry. Reviewer's remarks: (1) On two pages of this book Saccheri refers to his previous and equally original book Logica demonstrativa (Turin, 1697) to which 14 of the 16 pages of the editor's "Introduction" are devoted. (...) At the time of the first edition, 1920, the editor was apparently not acquainted with the secondary literature on Logica demonstrativa which continued to grow in the period preceding the second edition \ref[see D. J. Struik, in Dictionary of scientific biography, Vol. 12, 55--57, Scribner's, New York, 1975]. Of special interest in this connection is a series of three articles by A. F. Emch [Scripta Math. 3 (1935), 51--60; Zbl 10, 386; ibid. 3 (1935), 143--152; Zbl 11, 193; ibid. 3 (1935), 221--333; Zbl 12, 98]. (2) It seems curious that modern writers believe that demonstration of the "nondeducibility" of the parallel postulate vindicates Euclid whereas at first Saccheri seems to have thought that demonstration of its "deducibility" is what would vindicate Euclid. Saccheri is perfectly clear in his commitment to the ancient (and now discredited) view that it is wrong to take as an "axiom" a proposition which is not a "primal verity", which is not "known through itself". So it would seem that Saccheri should think that he was convicting Euclid of error by deducing the parallel postulate. The resolution of this confusion is that Saccheri thought that he had proved, not merely that the parallel postulate was true, but that it was a "primal verity" and, thus, that Euclid was correct in taking it as an "axiom". As implausible as this claim about Saccheri may seem, the passage on p. 237, lines 3--15, seems to admit of no other interpretation. Indeed, Emch takes it this way. (3) As has been noted by many others, Saccheri was fascinated, if not obsessed, by what may be called "reflexive indirect deductions", indirect deductions which show that a conclusion follows from given premises by a chain of reasoning beginning with the given premises augmented by the denial of the desired conclusion and ending with the conclusion itself. It is obvious, of course, that this is simply a species of ordinary indirect deduction; a conclusion follows from given premises if a contradiction is deducible from those given premises augmented by the denial of the conclusion---and it is immaterial whether the contradiction involves one of the premises, the denial of the conclusion, or even, as often happens, intermediate propositions distinct from the given premises and the denial of the conclusion. Saccheri seemed to think that a proposition proved in this way was deduced from its own denial and, thus, that its denial was self-contradictory (p. 207). Inference from this mistake to the idea that propositions proved in this way are "primal verities" would involve yet another confusion. The reviewer gratefully acknowledges extensive communication with his former doctoral students J. Gasser and M. Scanlan. ADDED 14 March 14, 2015: (1) Wikipedia reports that many of Saccheri's ideas have a precedent in the 11th Century Persian polymath Omar Khayyám's Discussion of Difficulties in Euclid, a fact ignored in most Western sources until recently. It is unclear whether Saccheri had access to this work in translation, or developed his ideas independently. (2) This book is another exemplification of the huge difference between indirect deduction and indirect reduction. Indirect deduction requires making an assumption that is inconsistent with the premises previously adopted. This means that the reasoner must perform a certain mental act of assuming a certain proposition. It case the premises are all known truths, indirect deduction—which would then be indirect proof—requires the reasoner to assume a falsehood. This fact has been noted by several prominent mathematicians including Hardy, Hilbert, and Tarski. Indirect reduction requires no new assumption. Indirect reduction is simply a transformation of an argument in one form into another argument in a different form. In an indirect reduction one proposition in the old premise set is replaced by the contradictory opposite of the old conclusion and the new conclusion becomes the contradictory opposite of the replaced premise. Roughly and schematically, P,Q/R becomes P,~R/~Q or ~R, Q/~P. Saccheri’s work involved indirect deduction not indirect reduction. (3) The distinction between indirect deduction and indirect reduction has largely slipped through the cracks, the cracks between medieval-oriented logic and modern-oriented logic. The medievalists have a heavy investment in reduction and, though they have heard of deduction, they think that deduction is a form of reduction, or vice versa, or in some cases they think that the word ‘deduction’ is the modern way of referring to reduction. The modernists have no interest in reduction, i.e. in the process of transforming one argument into another having exactly the same number of premises. Modern logicians, like Aristotle, are concerned with deducing a single proposition from a set of propositions. Some focus on deducing a single proposition from the null set—something difficult to relate to reduction. (shrink)

Plena are large-scale macro-totalities appropriate to the realms of all facts, all truths, and all things. Our attempt here is to take some first technical steps toward an adequate conception of plena.