Abduction is considered the most powerful, but also the most controversially discussed type of inference. Based on an analysis of Peirce’s retroduction, Lipton’s Inference to the Best Explanation and other theories, a new theory of abduction is proposed. It considers abduction not as intrinsically explanatory but as intrinsically conditional: for a given fact, abduction allows one to infer a fact that implies it. There are three types of abduction: Selective abduction selects an already known conditional whose consequent is the given (...) fact and infers that its antecedent is true. Conditional-creative abduction creates a new conditional in which the given fact is the consequent and a defined fact is the antecedent that implies the given fact. Propositional-conditional-creative abduction assumes that the given fact is implied by a hitherto undefined fact and thus creates a new conditional with a new proposition as antecedent. The execution of abductive inferences is specified by theory-specific patterns. Each pattern consists of a set of rules for both generating and justifying abductive conclusions and covers the complete inference process. Consequently, abductive inferences can be formalised iff the whole pattern can be formalised. The empirical consistency of the proposed theory is demonstrated by a case study of Semmelweis' research on puerperal fever. (shrink)

Reverse inference is a crucial inferential strategy used in cognitive neuroscience to derive conclusions about the engagement of cognitive processes from patterns of brain activation. While widely employed in experimental studies, it is now viewed with increasing scepticism within the neuroscience community. One problem with reverse inference is that it is logically invalid, being an instance of abduction in Peirce’s sense. In this paper, we offer the first systematic analysis of reverse inference as a form of abductive reasoning and highlight (...) some relevant implications for the current debate. We start by formalising an important distinction that has been entirely neglected in the literature, namely the distinction between weak and strong reverse inference. Then, we rely on case studies from recent neuroscientific research to systematically discuss the role and limits of both strong and weak reverse inference; in particular, we offer the first exploration of weak reverse inference as a discovery strategy within cognitive neuroscience. (shrink)

It is usually accepted that deductions are non-informative and monotonic, inductions are informative and nonmonotonic, abductions create hypotheses but are epistemically irrelevant, and both deductions and inductions can’t provide new insights. In this article, I attempt to provide a more cohesive view of the subject with the following hypotheses: (1) the paradigmatic examples of deductions, such as modus ponens and hypothetical syllogism, are not inferential forms, but coherence requirements for inferences; (2) since any reasoner aims to be coherent, any inference (...) must be deductive; (3) a coherent inference is an intuitive process where the premises should be taken as sufficient evidence for the conclusion, which on its turn should be viewed as necessary evidence for the premises in some modal range; (4) inductions, properly understood, are abductions, but there are no abductions beyond the fact that in any inference the conclusion should be regarded as necessary evidence for the premises; (5) monotonicity is not only compatible with the retraction of past inferences given new information, but it is a requirement for it; (6) this explanation of inferences holds true for discovery processes, predictions and trivial inferences. (shrink)

ABSTRACT Abduction as a method for sociological explanation is increasingly gaining interest, but questions remain as to what exactly it is and how it differs from other methods of inquiry. This paper compares abduction as conceived in Peircean pragmatism with the critical realist concept of retroduction. I argue that abduction in the Peircean sense and retroduction in the critical realist sense refer to different, but complementary, modes of inference. Abductive conclusions provide the starting point for retroductive inferences; the latter inform (...) the tenability of the former. Together, abduction and retroduction contribute to theoretical explanation. (shrink)

In science and everyday life, we often infer that something is true because it would explain some set of facts better than any other hypothesis we can think of. But what if we have reason to believe that there is a better way to explain these facts that we just haven't thought of? Wouldn't that undermine our warrant for believing the best available explanation? Many philosophers have assumed that we can solve such underconsideration problems by stipulating that a hypothesis should (...) not only be 'the best' explanation available; rather, it should also be 'good enough'. Unfortunately, however, the only current suggestion for what it might mean to say that an explanation is 'good enough' is, well, not good enough. This paper aims to provide a better account of what is required for an explanatory hypothesis to be considered 'good enough'. In brief, the account holds that a `good enough' hypothesis is one that has gone through a process that I call explanatory consolidation, in which accumulating evidence and failed attempts to formulate better alternatives gradually make it more plausible that the explanation we currently have is better than any other that could be formulated. (shrink)

The relationship between Peircean abduction and the modern notion of Inference to the Best Explanation is a matter of dispute. Some philosophers, such as Harman :88–95, 1965) and Lipton, claim that abduction and IBE are virtually the same. Others, however, hold that they are quite different :503, 1998; Minnameier in Erkenntnis 60:75–105, 2004) and there is no link between them :419–442, 2009). In this paper, I argue that neither of these views is correct. I show that abduction and IBE have (...) important similarities as well as differences. Moreover, by bringing a historical perspective to the study of the relationship between abduction and IBE—a perspective that is lacking in the literature—I show that their differences can be well understood in terms of two historic developments in the history of philosophy of science: first, Reichenbach’s distinction between the context of discovery and the context of justification—and the consequent jettisoning of the context of discovery from philosophy of science—and second, underdetermination of theory by data. (shrink)

Explaining phenomena is a primary goal of science. Consequently, it is unsurprising that gaining a proper understanding of the nature of explanation is an important goal of science education. In order to properly understand explanation, however, it is not enough to simply consider theories of the nature of explanation. Properly understanding explanation requires grasping the relation between explanation and understanding, as well as how explanations can lead to scientific knowledge. This article examines the nature of explanation, its relation to understanding, (...) and how explanations are used to generate scientific knowledge via inferences to the best explanation. Studying these features and applications of explanation not only provides insight into a concept that is important for science education in its own right, but also sheds light on an aspect of recent debates concerning the so-called consensus view of nature of science (NOS). Once the relation between explanation, understanding, and knowledge is clear, it becomes apparent that science is unified in important ways. Seeing this unification provides some support for thinking that there are general features of NOS of the sort proposed by the consensus view and that teaching about these general features of NOS should be a goal of science education. (shrink)

_ Source: _Page Count 13 A promising response to the threat of external world skepticism involves arguing that our commonsense view of the world best explains the sensory experiences that we have. Since our commonsense view of the world best explains our evidence, we are justified in accepting this commonsense view of the world. Despite the plausibility of this Explanationist Response, it has recently come under attack. James Beebe has argued that only a version of the Explanationist Response that provides (...) an a priori justification of inference to the best explanation can hope to respond to two serious objections. Additionally, he has argued that providing such an a priori justification requires an acceptable account of a priori probability and that it is unclear whether such an account can be developed. In this paper I argue that Beebe fails to provide adequate support for either of these claims. (shrink)

An influential suggestion about the relationship between Bayesianism and inference to the best explanation holds that IBE functions as a heuristic to approximate Bayesian reasoning. While this view promises to unify Bayesianism and IBE in a very attractive manner, important elements of the view have not yet been spelled out in detail. I present and argue for a heuristic conception of IBE on which IBE serves primarily to locate the most probable available explanatory hypothesis to serve as a working hypothesis (...) in an agent’s further investigations. Along the way, I criticize what I consider to be an overly ambitious conception of the heuristic role of IBE, according to which IBE serves as a guide to absolute probability values. My own conception, by contrast, requires only that IBE can function as a guide to the comparative probability values of available hypotheses. This is shown to be a much more realistic role for IBE given the nature and limitations of the explanatory considerations with which IBE operates. (shrink)

Epistemic two-dimensional semantics, advocated by Chalmers and Jackson, among others, aims to restore the link between necessity and a priority seemingly broken by Kripke, by showing how armchair access to semantic intensions provides a basis for knowledge of necessary a posteriori truths. The most compelling objections to E2D are that, for one or other reason, the requisite intensions are not accessible from the armchair. As we substantiate here, existing versions of E2D are indeed subject to such access-based objections. But, we (...) moreover argue, the difficulty lies not with E2D but with the typically presupposed conceiving-based epistemology of intensions. Freed from that epistemology, and given the right alternative—one where inference to the best explanation provides the operative guide to intensions—E2D can meet access-based objections, and fulfill its promise of restoring the desirable link between necessity and a priority. This result serves as a central application of Biggs and Wilson, according to which abduction is an a priori mode of inference. (shrink)

Here we challenge the orthodoxy according to which abduction is an a posteriori mode of inference. We start by providing a case study illustrating how abduction can justify a philosophical claim not justifiable by empirical evidence alone. While many grant abduction's epistemic value, nearly all assume that abductive justification is a posteriori, on grounds that our belief in abduction's epistemic value depends on empirical evidence about how the world contingently is. Contra this assumption, we argue, first, that our belief in (...) abduction’s epistemic value is not and could not be justified a posteriori, and second, that attention to the roles experience plays in abductive justification supports taking abduction to be an a priori mode of inference. We close by highlighting how our strategy for establishing the a priority of abduction positively contrasts with strategies in Bonjour (1998), Swinburne (2001), and Peacocke (2004) aiming to establish the a priority of certain ampliative modes of inference or abductive principles. (shrink)

_ Source: _Page Count 14 Jonathan Vogel has argued in support of an explanationist response to skepticism in several works. Central to this explanationist response is the fact that our non-skeptical view of the world is a better explanation of our experiences than its skeptical rivals. Despite the plausibility of this response to skepticism, it is not without its critics. Recently, Matthew Gifford has argued that Vogel’s response has problems on two fronts. First, Gifford argues that Vogel’s strategy for showing (...) that the rwh is a better explanation than its skeptical rivals fails. Second, he argues that if Vogel’s strategy does succeed, then it accomplishes too much—it removes skeptical doubts when it should not. I argue that Gifford is mistaken on both accounts. (shrink)

In this paper, I consider the relationship between Inference to the Best Explanation and Bayesianism, both of which are well-known accounts of the nature of scientific inference. In Sect. 2, I give a brief overview of Bayesianism and IBE. In Sect. 3, I argue that IBE in its most prominently defended forms is difficult to reconcile with Bayesianism because not all of the items that feature on popular lists of “explanatory virtues”—by means of which IBE ranks competing explanations—have confirmational import. (...) Rather, some of the items that feature on these lists are “informational virtues”—properties that do not make a hypothesis \ more probable than some competitor \ given evidence E, but that, roughly-speaking, give that hypothesis greater informative content. In Sect. 4, I consider as a response to my argument a recent version of compatibilism which argues that IBE can provide further normative constraints on the objectively correct probability function. I argue that this response does not succeed, owing to the difficulty of defending with any generality such further normative constraints. Lastly, in Sect. 5, I propose that IBE should be regarded, not as a theory of scientific inference, but rather as a theory of when we ought to “accept” H, where the acceptability of H is fixed by the goals of science and concerns whether H is worthy of commitment as research program. In this way, IBE and Bayesianism, as I will show, can be made compatible, and thus the Bayesian and the proponent of IBE can be friends. (shrink)

This article provides a critical realist (CR) alternative to the standard approaches to Thematic Analysis (TA) in qualitative research, namely the Braun-Clarke approach (reflexivity while coding themes), the Attride-Sterling approach (clustering basic, global and organizing themes), and Boyatzis' approach (clarifying criteria for assessing the absence/presence of themes in the raw material). In the CR traditions, the experiential themes /inferential themes /dispositional themes and the data/codes/themes distinctions have been proposed recently as the methodological device for answering the question “what is the (...) theme”. The aim of this article is threefold. First, I bring to light the inconsistencies of the non-CR approaches to TA, second, I discuss critically the CR approaches to TA and finally I offer a CR-based approach to TA which builds upon them by introducing specific innovations from social network analysis which make abductive and retroductive reasoning a shareable procedure for answering “what is the theme?”. (shrink)

Under the rubric of understanding the problem of explainability of AI in terms of abductive cognition, I propose to review the lessons from AlphaGo and her more powerful successors. As AI players in Baduk have arrived at superhuman level, there seems to be no hope for understanding the secret of their breathtakingly brilliant moves. Without making AI players explainable in some ways, both human and AI players would be less-than omniscient, if not ignorant, epistemic agents. Are we bound to have (...) less explainable AI Baduk players as they make further progress? I shall show that the resolution of this apparent paradox depends on how we understand the crucial distinction between abduction and inference to the best explanation. Some further philosophical issues arising from explainable AI will also be discussed in connection with this distinction. (shrink)

In this paper, I discuss the ways in which epistemic anxiety promotes well-being, specifically by examining the positive contributions that feelings of epistemic anxiety make toward intellectually virtuous inquiry. While the prospects for connecting the concept of epistemic anxiety to the two most prominent accounts of intellectual virtue, i.e., “virtue-reliabilism” and “virtue-responsibilism”, are promising, I primarily focus on whether the capacity for epistemic anxiety counts as an intellectual virtue in the reliabilist sense. As I argue, there is a close yet (...) unexplored connection between feelings of epistemic anxiety and the form of inference commonly known as “Inference to the Best Explanation” (IBE). Specifically, I argue that both the recognition that some fact requires an explanation—a necessary first step in applying IBE—and the subsequent motivation to employ IBE are typically facilitated by feelings of epistemic anxiety. So, provided IBE is truth-conducive the capacity for epistemic anxiety should count as an intellectual virtue in the reliabilist sense. After outlining my main argument, I address the challenge that the capacity for epistemic anxiety has the potential to be misleading. To respond to this challenge, I discuss how our recognition that a fact requires an explanation must in part be a species of practical knowledge, rather than theoretical knowledge. For the agent to skillfully distinguish between facts that require an explanation and facts that do not, she must develop the virtuous disposition to feel the appropriate amount of epistemic anxiety. Despite the many negative aspects associated with anxiety, as I conclude, being disposed to feel the appropriate amount of epistemic anxiety is ultimately good for us. (shrink)

This article generalizes the explanationist account of inference to the best explanation. It draws a clear distinction between IBE and abduction and presents abduction as the first step of IBE. The second step amounts to the evaluation of explanatory power, which consist in the degree of explanatory virtues that a hypothesis exhibits. Moreover, even though coherence is the most often cited explanatory virtue, on pain of circularity, it should not be treated as one of the explanatory virtues. Rather, coherence should (...) be equated with explanatory power and considered to be derivable from the other explanatory virtues: unification, explanatory depth and simplicity. (shrink)

Although the inferring of explanations plays an important role in both our everyday lives and in the workings of science, I argue that inference to the best explanation as it is commonly conceived is often not the best way to capture this sort of reasoning. I suggest that a different form of reasoning – so-called immediate explanatory inference – is instead often much better suited to this task. This is a form of inference in which we are justified in believing (...) explanations for the evidence before us purely in virtue of this evidence, and not in virtue of the evidence plus some general principle or rule of non-deductive reasoning. I defend the idea of such a notion of inference, and argue that it plays a central role in both ordinary life and science. (shrink)

Este artigo pretende oferecer uma apresentação e análise do artigo “On the distinction between Peirce’s abduction and Lipton’s Inference to the best explanation”, de Daniel Campos. Apresentamos uma reconstrução da argumentação de Campos a favor da distinção entre abdução e inferência da melhor explicação, enfatizando a interpretação de Campos sobre inferência da melhor explicação na perspectiva de Peter Lipton. Em contraposição a Campos, que defende uma distinção parcial entre abdução e a inferência da melhor explicação, neste artigo sugerimos uma distinção (...) completa entre as formas de raciocínio. (shrink)

This book examines the philosophical conception of abductive reasoning as developed by Charles S. Peirce, the founder of American pragmatism. It explores the historical and systematic connections of Peirce's original ideas and debates about their interpretations. Abduction is understood in a broad sense which covers the discovery and pursuit of hypotheses and inference to the best explanation. The analysis presents fresh insights into this notion of reasoning, which derives from effects to causes or from surprising observations to explanatory theories. The (...) author outlines some logical and AI approaches to abduction as well as studies various kinds of inverse problems in astronomy, physics, medicine, biology, and human sciences to provide examples of retroductions and abductions. The discussion covers also everyday examples with the implication of this notion in detective stories, one of Peirce’s own favorite themes. The author uses Bayesian probabilities to argue that explanatory abduction is a method of confirmation. He uses his own account of truth approximation to reformulate abduction as inference which leads to the truthlikeness of its conclusion. This allows a powerful abductive defense of scientific realism. This up-to-date survey and defense of the Peircean view of abduction may very well help researchers, students, and philosophers better understand the logic of truth-seeking. (shrink)

In this article, I compare two varieties of abduction as reconstructive models for analysing discovery. The first is 'Hansonian abduction', which is based on N. R. Hanson's formulations of abduction. The other is 'Harmanian abduction', the Inference to the Best Explanation (IBE) model, formulated especially by Gilbert Harman. Peter Lipton has analysed processes of discovery on the basis of his developed form of Harmanian abduction. I argue that Hansonian abduction would, however, be a more apt model for this purpose. As (...) an example, I reconstruct, in a Hansonian manner, Ignaz Semmelweis's research on childbed fever and compare it to the IBE reconstruction of Lipton. I argue that Hansonian abduction is in accordance with Lipton's aim of taking into account the distinction between actual and potential explanations on the one hand, and between likely and lovely explanations on the other. I maintain that a developed version of Hansonian abduction combined with loveliness gives an important, new conceptual means for analysing processes of discovery. (shrink)

The aim of this article is to analyse the kind of inference used in the reconstruction of proto-languages. Hypothesis is at the core of this reconstruction process and this, together with the structure of reasoning involved, indicates abductive reasoning. We analyse abductive reasoning, and specify its nuances and particularities. The novelty we introduce is the importance of context as we focus on a form of abduction that goes beyond the context in which the scientific work is being developed by incorporating (...) contexts from other sciences. Therefore, an intercontextual chain of inference can be part of abductive reasoning processes and the resulting hypothesis remains provisional. Several disciplines, such as archaeology, history and linguistics, play a cognitive role in the reconstruction of proto-languages, thus requiring more than one context. We use the case of the reconstruction of proto-Semitic and the unexpected fact of the Ugarit and Ebla discoveries (plus Amorite names). This sample may shed light on the use of abduction to explain certain scientific practices. (shrink)

I argue against the tendency in the philosophy of science literature to link abduction to the inference to the best explanation (IBE), and in particular, to claim that Peireean abduction is a conceptual predecessor to IBE. This is not to discount either abduction or IBE. Rather the purpose of this paper is to clarify the relation between Peireean abduction and IBE in accounting for ampliative inference in science. This paper aims at a proper classification—not justification—of types of scientific reasoning. In (...) particular, I claim that Peireean abduction is an in-depth account of the process of generating explanatory hypotheses, while IBE, at least in Peter Lipton's thorough treatment, is a more encompassing account of the processes both of generating and of evaluating scientific hypotheses. There is then a two-fold problem with the claim that abduction is IBE. On the one hand, it conflates abduction and induction, which are two distinct forms of logical inference, with two distinct aims, as shown by Charles S. Peirce; on the other hand it lacks a clear sense of the full scope of IBE as an account of scientific inference. (shrink)

Abduction is a widely used but deductively invalid type of reasoning. In this paper I will develop a tool for the assessment of argumentation based on abduction that can be used to analyse and evaluate the type of argumentation as it occurs in institutionalized contexts like science and medical diagnosis. I will summarize the most important definitions of abduction and propose an argumentative pattern on the basis of a critical examination of two extant dialectical accounts of the argument scheme involved.

We examine Charles S. Peirce's mature views on the logic of science, especially as contained in his later and still mostly unpublished writings. We focus on two main issues. The first concerns Peirce's late conception of retroduction. Peirce conceived inquiry as performed in three stages, which correspond to three classes of inferences: abduction or retroduction, deduction, and induction. The question of the logical form of retroduction, of its logical justification, and of its methodology stands out as the three major threads (...) in his later writings. The other issue concerns the second stage of scientific inquiry, deduction. According to Peirce's later formulation, deduction is divided not only into two kinds but also into two sub-stages: logical analysis and mathematical reasoning, where the latter is either corollarial or theorematic. Save for the inductive stage, which we do not address here, these points cover the essentials of Peirce's latest thinking on the l.. (shrink)

The main theme of the article, which by genre falls into the area of semiotically influenced philosophy, is a reflection on the relationship between the human and the non-human, using two partial but parallel discourses. The first discourse is the perspective of general semiotics, which is defined in the article on the basis of two distinct forms of rationality that, in different guises, still intervene in debates about the nature of the humanities and social sciences today. The first form of (...) this rationality is semiological, which can be classified under the encyclopaedic rubric of structuralism, and which has its main source of inspiration in general linguistics and its continuation in philosophical anti-humanism. The second perspective has its origins in Peirce’s logicist theory of the sign and his pragmatist metaphysics, and opens up thinking about the sign, the human, and the non-human to a non-language-centric view of the world. Despite their demonstrable theoretical and methodological incompatibility, the present text treats them as incompatible but largely complementary perspectives. It is in their mutual exposition that one can see the moments in which the view of modern human as a semiological and semiotic animal takes shape. The text brings this fundamental and founding theoretical schism into focus by examining two images from post/modern art: Ted Chiang’s “The Great Silence” and Jorge Luis Borges’ “Averroës’s Search.”. (shrink)

The aim of this paper is to investigate the relationship between information and abductive reasoning in the context of problem-solving, focusing on non-human animals. Two questions guide our investigation: What is the relation between information and abductive reasoning in the context of human and non-human animals? Do non-human animals perform discovery based on inferential processes such as abductive reasoning? In order to answer these questions, we discuss the semiotic concept of information in relation to the concept of abductive reasoning and, (...) more specifically, to the notion of manipulative abduction proposed by Magnani. Finally, we investigate a case study of corvids’ intelligence, namely, their capacity of causal cognition. (shrink)

In philosophy of science, the literature on abduction and the literature on styles of thinking have existed almost totally in parallel. Here, for the first time, we bring them together and explore their mutual relevance. What is the consequence of the existence of several styles of scientific thinking for abduction? Can abduction, as a general creative mode of inference, have distinct characteristic forms within each style? To investigate this, firstly, we present the concept of abduction; secondly we analyze what is (...) understood by styles of thinking; thirdly, we give some comments on abduction and styles of thinking by analyzing examples of scientific discovery or innovation within each style. We develop a case-based comparative investigation of creative aspects of abductive reasoning with examples drawn from different styles of scientific thinking and doing as understood by the Crombie/hacking tradition. We argue that abduction, as a general mode of reasoning, can have a variety of specific expressions enabled and constrained by the styles of scientific thinking. Finally, we draw some conclusions on the relationship between abduction and styles of thinking suggesting that scientific discovery is a dynamical goal-directed activity within the scientific community that benefits from distinct styles of thinking and doing research. (shrink)

The main theme of the article, which by genre falls into the area of semiotically influenced philosophy, is a reflection on the relationship between the human and the non-human, using two partial but parallel discourses. The first discourse is the perspective of general semiotics, which is defined in the article on the basis of two distinct forms of rationality that, in different guises, still intervene in debates about the nature of the humanities and social sciences today. The first form of (...) this rationality is semiological, which can be classified under the encyclopaedic rubric of structuralism, and which has its main source of inspiration in general linguistics and its continuation in philosophical anti-humanism. The second perspective has its origins in Peirce’s logicist theory of the sign and his pragmatist metaphysics, and opens up thinking about the sign, the human, and the non-human to a non-language-centric view of the world. Despite their demonstrable theoretical and methodological incompatibility, the present text treats them as incompatible but largely complementary perspectives. It is in their mutual exposition that one can see the moments in which the view of modern human as a semiological and semiotic animal takes shape. The text brings this fundamental and founding theoretical schism into focus by examining two images from post/modern art: Ted Chiang’s “The Great Silence” and Jorge Luis Borges’ “Averroës’s Search.”. (shrink)

The underconsideration argument against inference to the best explanation and scientific realism holds that scientists are not warranted in inferring that the best theory is true, because scientists only ever conceive of a small handful of theories at one time, and as a result, they may not have considered a true theory. However, antirealists have not developed a detailed alternative account of why explanatory inference nevertheless appears so central to scientific practice. In this paper, I provide new defences against some (...) recent objections to the underconsideration argument, while also developing an account of explanatory inference that both survives these criticisms and does not entail realism. (shrink)

Clinical diagnostic medicine is an experimental science based on observation, hypothesis making, and testing. It is an use dynamic process that involves observation and summary, diagnostic conjectures, testing, review, observation and summary, new or revised conjectures, i.e. it is an iterative process. It can then be said that diagnostic hypotheses are also ‘observation-laden’. My aim is to enlarge on the strategies of medical diagnosis as these are meshed in training and clinical experience—that is, to describe the patterns of reasoning used (...) by experienced clinicians under different diagnostic circumstances and how these patterns of inquiry allow further insight into the evaluation and treatment of patients. I do not aim to present a theory and illustrate it with examples; I wish rather am to let a realistic example, similar to actual clinical scenarios, direct the exposition. To this end, I introduce an account of medical diagnosis—briefly comparing and contrasting it to other accounts—in order to focus on discussing the process of diagnosis through a detailed clinical case. (shrink)

A light form of value realism is defended according to which objective properties of comparison objects make value comparisons true or false. If one object has such a better-making property and another lacks it, this is sufficient for the truth of a corresponding value comparison. However, better-making properties are only necessary and usually not sufficient parts of the justifications of value comparisons. The account is not reductionist; it remains consistent with error-theoretic positions and the view that there are normative facts.