Tässä artikkelissa käsittelen Descartesin ikuisten totuuksien välttämättömyyteen liittyvää ongelmaa. Teoksessa Mietiskelyjä ensimmäisestä filosofiasta (1641–1642) Descartes nostaa esiin käsitteen ikuisista totuuksista, käyttäen esimerkkinään kolmiota. Kolmion muuttumattomaan ja ikuiseen luontoon kuuluu esimerkiksi, että sen kolme kulmaa ovat yhteenlaskettuna 180°. Se on totta kolmiosta, vaikka yhtään yksittäistä kolmiota ei olisi koskaan ollutkaan olemassa. Eräät ajattelemieni asioiden piirteet ovat siis Descartesin mukaan ajattelustani riippumattomia. Ikuisia totuuksia ovat ainakin matemaattiset ja geometriset tosiseikat sekä ristiriidan laki. Samoin Descartesin kuuluisa lause “ajattelen, siis olen” lukeutuu ikuisten totuuksien (...) joukkoon. Descartesin ikuiset totuudet olisivatkin siis loogisesti välttämättömiä. Niillä on kyseinen olemus riippumatta ulkoisten kohteiden olemassaolosta tai siitä, ajattelenko niitä lainkaan. Kuitenkin kirjeenvaihdossaan Descartes pitää itsepintaisesti kiinni käsityksestään, että ikuiset totuudet ovat Jumalan vapaasti luomia ja Jumala olisi voinut luoda ne erilailla. Näin ollen luodut ikuiset totuudet eivät tarkkaan ottaen olisikaan välttämättömiä vaan kontingentteja. Ne voisivat olla myös toisella tavalla. Artikkelin alkuun esittelen Descartesin modaalista metafysiikkaa sekä luotujen ikuisten totuuksien kontingenttiudesta seuraavia tulkinnallisia vaikeuksia. Tämän jälkeen pureudun kolmeen erilaiseen ratkaisuyritykseen kommentaarikirjallisuudessa (Frankfurt 1977; Curley 1984 & Bennett 1994) ja osoitan, miksi ne eivät riitä vastaamaan ongelmaan. Lopussa vedän johtopäätöksiä ja luonnostelen mahdollisen ratkaisun. (shrink)

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)

This paper is about the pragmatic inferences in play as conversational implicatures (Grice, P. 1989. Studies in the way of words. Cambridge, MA: Harvard University Press) occur. First, it constructs the deductivism versus abductivism debate that transpires from the extant literature but is rarely elaborated. Against deductivism, the paper argues that implicating inferences in conversational implicatures can instantiate an abductive logical form, as abductivism suggests. Against abductivism, however, it grants to deductivism that implicating inferences can have a deductive form provided (...) the latter is of a defeasible type. In sum, it thus argues for pluralist defeasibilism. Second, it turns to the issue of the ontological nature of implicating inferences and advocates normative inferentialism, on which these inferences are not primarily real psychological processes but rules of the practice of implicating. While this allows for the possibility of their psychological instantiation, to be sure, the paper also insists that psychological inferring processes in implicatures are neither necessarily isomorphic to the aforementioned rules nor even necessarily occur as an implicature occurs. (shrink)

This paper presents a dual intention model (DIM) of demonstrations as actions to show the agentive nature of demonstrations. According to the DIM, demonstrations are complex actions that contain as components at least three elements: an abductive intention, a deictic intention, and a basic ostensive act of indication. This paper unpacks these three components and discusses their roles from the viewpoint of the philosophy of action and the philosophy of language. It also shows how the DIM applies in selected practical (...) examples and explains the merits of the model in the context of other views on demonstrations and demonstratives. (shrink)

Scientists routinely solve the problem of supplementing one’s store of variables with new theoretical posits that can explain the previously inexplicable. The banality of success at this task obscures a remarkable fact. Generating hypotheses that contain novel variables and accurately project over a limited amount of additional data is so difficult—the space of possibilities so vast—that succeeding through guesswork is overwhelmingly unlikely despite a very large number of attempts. And yet scientists do generate hypotheses of this sort in very few (...) tries. I argue that this poses a dilemma: either the long history of scientific success is a miracle, or there exists at least one method or algorithm for generating novel hypotheses with at least limited projectibility on the basis of what’s available to the scientist at a time, namely a set of observations, the history of past conjectures, and some prior theoretical commitments. In other words, either ordinary scientific success is miraculous or there exists a logic of discovery at the heart of actual scientific method. (shrink)