Kant maintains that his Critique of Pure Reason follows a “synthetic method” which he distinguishes from the analytic method of the Prolegomena by saying that the Critique “rests on no other science” and “takes nothing as given except reason itself”. The paper presents an account of the synthetic method of the Critique, showing how it is related to Kant’s conception of the Critique as the “science of an a priori judging reason”. Moreover, the author suggests, understanding its (...) class='Hi'>synthetic method sheds light on the structure of the Transcendental Deduction, and its function in the work as a whole. (shrink)

According to the received view, Charles S. Peirce's theory of diagrammatic reasoning is derived from Kant's philosophy of mathematics. For Kant, only mathematics is constructive/synthetic, logic being instead discursive/analytic, while for Peirce, the entire domain of necessary reasoning, comprising mathematics and deductive logic, is diagrammatic, i.e. constructive in the Kantian sense. This shift was stimulated, as Peirce himself acknowledged, by the doctrines contained in Friedrich Albert Lange's Logische Studien (1877). The present paper reconstructs Peirce's reading of (...) Lange's book, and illustrates what, according to Peirce, was right and what was problematic in Lange's account of reasoning. It further seeks to explain how Peirce's theory of deductive reasoning was a combination of Kant's philosophy of mathematics and Lange's philosophy of logic. (shrink)

There is a broad debate in contemporary philosophy of logic on the informativeness of proofs. In this context, informative proofs are demonstrations whose premises do not include the content of the conclusion. D’Agostino and Floridi (Synthese 167(2):271–315, 2009) claimed that proofs are informative if they use _virtual information_. In their terminology, this is the data carried by _dischargeable hypotheses_, assumptions entertained during proof and eliminated before concluding. Although these authors capture several cases of informative demonstrations, they do not explain the (...) nature of virtual information. Why does the use of dischargeable hypotheses increase the informativeness of a demonstration? Following a Kantian inspiration, D’Agostino and Floridi claim that virtual information adds a synthetic feature to our proofs. However, this appeal to Kantianism is misleading: for Kant, mathematics is synthetic because it requires the construction of concepts in pure intuition. On the other hand, the entertainment of provisional hypotheses does not seem to involve the construction of figures in (transcendental) imagination. Exploring a _dialogical_ characterization of logic, I suggest that virtual information results from the dynamics between a reasoner and her audience. When a reasoner provisionally assumes _P_, she enacts potential interlocutors who commit to _P_. Thus, “virtual information” denotes the content of some assumptions of the possible audience of a demonstration. This process of departing from one’s original premises to embrace the suppositions of other people is informative, but it is not synthetic: in this way, the reasoner does not entertain intuitions but only needs to reason through the conceptual content of other people’s premises. (shrink)

The purpose of the third section of Kant’s Groundwork is to prove the possibility of the categorical imperative. In the end of the second section, Kant establishes that a proof like this is necessary to show that morality is ‘something’ and ‘not a chimerical idea without any truth’ or a ‘phantom’. Since the categorical imperative was established as a synthetic a priori practical proposition, in order to prove its possibility it is necessary ‘to go beyond cognition of objects to (...) a critique of the subject, that is, of pure practical reason’. Kant names this kind of proof a deduction. The present paper intends to show the argument whose purpose is to justify the categorical imperative; show that the argument is a transcendental deduction; present the argument as it is reconstructed by Allison, and show that, although it seems compelling, the position of the commentator could not be accepted by Kant himself. (shrink)

KANT’S GOAL IN THE TRANSCENDENTAL DEDUCTION was to demonstrate that the categories are applicable to objects of sensible intuition. He carried out this task by disclosing the necessity of a transcendental synthesis. In the Transcendental Deduction in the second edition of the Critique of Pure Reason transcendental synthesis has two subspecies: synthesis intellectualis and synthesis speciosa. The distinction between the two types of transcendental synthesis is also mirrored in the structure of the proof of the B Deduction. As several commentators (...) have noted, the B Deduction in fact contains two parts. Each part seems to provide an account of a distinctive kind of transcendental synthesis. The first part provides an account of intellectual synthesis while the second part provides an account of figurative synthesis. (shrink)

In this paper, I will show that Sherlock Holmes was a good logician, according to the standard of the 19th century, both in his character and knowledge (sections 2 and 3). Holmes, in all probability, knew William Stanley Jevons’ clarification of deductive reasoning in terms of “logical alphabets” (section 4). And in view of his use of “analytic-synthetic” distinction and “analytic reasoning,” I will argue that Holmes knew rather well philosophy too, as far as logic and (...) methodology are concerned (section 5). Further, I have argued that Holmes introduced new twists (presumably, following Jevons) into analytic reasoning: application to reasoning as regards causal sequences, and probabilistic elimination of hypotheses (sections 6 and 7). Also, in this context, I will clarify the significance of Holmes’ metaphor of the “little attic”: without fine assortment in your brain, it is hard to devise promising hypotheses (section 8). Finally, presenting a simple model of probabilistic inference, which became prevalent in the 19th century (section 9), I claim that the essence of Holmes’ reasoning consists of probabilistic inferences, “balance probabilities and choose the most likely,” which is nothing but probabilistic elimination of hypotheses in the light of evidence. I also argue that my claim fits in well with the text of Holmes stories (section 10). (shrink)

Munsat’s objective in collecting eleven selections on the analytic-synthetic distinction is to acquaint the beginning or intermediate student with the major aspects of the issue. The selections are presented in historical sequence and Munsat has effectively edited the works such that one can easily follow the development of the distinction without having to contend with excessive peripheral material. The editor provides a short introduction to the varieties of truth as well as prefatory notes to each selection. Beginning with brief (...) selections from Leibniz and Hobbes, the treatment of necessary and contingent truths is traced through Kant and Mill. The Mill selection, "Of Demonstration, and Necessary Truths," deals with the inductive foundations of the deductive sciences and mathematics. This line of investigation reaches its climax in the Frege passages on the nature of arithmetical propositions and Russell’s "What is an Empirical Science?" Of particular importance are portions of three classic contributions to the analytic-synthetic distinction: Kant’s Introduction to the Critique of Pure Reason, W. V. Quine’s critical "Two Dogmas of Empiricism," and the rebuttal to Quine’s attack by Grice and Strawson, "In Defense of a Dogma." Finally, the segment of J. L. Austin’s "The Meaning of a Word" could just as well have been excluded in the interest of continuity and in deference to some more appropriate selection. Munsat has included a useful nineteen-page bibliography.—B. G. H. (shrink)

Considering the instability of nonlinear dynamics, the deductive inference rule Modus ponens itself is not enough to guarantee the validity of reasoning sequences in the real physical world, and similar results cannot necessarily be obtained from similar causes. Some kind of stability hypothesis should be added in order to draw meaningful conclusions. Hence, the uncertainty of deductive inference appears to be like that of inductive inference, and the asymmetry between deduction and induction becomes unrecognizable such as to (...) undermine the basis for the fundamental cleavage between analytic truth and synthetic truth, as W. V. O. Quine pointed out. Induction is not inferior to deduction from a pragmatic point of view. (shrink)

I argue that Kant’s primary epistemological concern in the Critique of Pure Reason’s transcendental deduction is empirical cognition. I show how empirical cognition is best understood as “rational sensory discrimination”: the capacity to discriminate sensory objects through the use of concepts and with a sensitivity to the normativity of reasons. My dissertation focuses on Kant’s starting assumption of the transcendental deduction, which I argue to be the thesis that we have empirical cognition. I then show how Kant’s own subjective deduction (...) fleshes out his conception of empirical cognition and is intertwined with key steps in the transcendental deduction’s arguments that the categories have objective validity and that we have synthetic a priori cognition. (shrink)

In this chapter, I expound Hegel’s critique of Kant, which he first and most elaborately presented in his early essay Faith and Knowledge (1802), by focusing on the criticism that Hegel levelled against Kant’s (supposedly) arbitrary subjectivism about the categories. This relates to the restriction thesis of Kant’s transcendental idealism: categorially governed empirical knowledge only applies to appearances, not to things in themselves, and so does not reach objective reality, according to Hegel. Hegel claims that this restriction of knowledge to (...) appearances is unwarranted merely on the basis of Kant’s own principle of transcendental apperception, and just stems from Kant’s empiricist bias. He argues that Kant’s principle of apperception as the foundational principle of knowledge is in fact incompatible with his empiricism. Hegel rightly appraises the centrality of transcendental apperception for the constitution of objectivity. But he is wrong about its incompatibility with Kant’s empirical realism. By virtue of a misapprehension of the formal distinction between the accompanying ‘I think’, i.e. the analytical principle of apperception, and what Hegel calls “the true ‘I’” of the original-synthetic unity of apperception, Hegel unjustifiably prises apart the productive imagination, which is supposedly this “true ‘I’”, and the understanding, which is supposedly just a derivative, subjective form of the productive imagination; the latter, according to Hegel, is Reason or Being itself, and is the truly objective. This deflationary reading of the understanding, which hypostatises the imagination as the supreme principle, rests on a distortion of key elements of Kant’s theory of apperception. In this chapter, I show that Hegel’s charge of inconsistency against Kant, namely, Hegel’s claim that the principle of apperception as the highest principle of cognition does not comport with Kant’s restriction thesis, is the direct consequence of a psychological misreading of Kant’s subjectivism. (shrink)

The distinction between the syntactic and the semantic approach to scientific theories emerged in formal philosophy of science. The semantic approach is commonly considered more advanced and more successful than the syntactic one, but the transition from the one approach to the other was not brought about without any loss. In essence, it is the formal analysis of atomic propositions and the analysis of deductive reasoning that dropped out of consideration in at least some of the elaborated versions (...) of the semantic approach. In structuralist theory of science, as founded by Sneed and Stegmüller, the focus is on global propositions concerning the question of whether or not certain empirical systems satisfy a set-theoretic predicate that encodes the axioms of a scientific theory. Hence, an analysis of deductive reasoning from atomic premisses with the help of a given theory is missing. The objective of the present paper is to develop a deductive system on the basis of the structuralist framework. This system comes with a novel formulation of empirical propositions in structuralism. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Concepts, Judgments, and Unity in Kant's Metaphysical Deduction of the Relational Categories CHARLES NUSSBAUM 1. INTRODUCTION TO ANY ATTENTIVEREADERof the section of the Critique of Pure Reason' known as the "Metaphysical Deduction of the Categories" (A67/B92-A83/B to9), one paragraph in that section stands out particularly by virtue of its special importance for Kant's developing argument: The same function Which gives unity to the various representations in ajudgment also gives (...) unity to the mere synthesis of various representations in an intuition; and this unity, in its most general expression, we entitle the pure concept of the understanding. The same understanding, through the same operations by which in concepts, by means of analytical unity, it produced the logical form of a judgment, also introduces a transcendental content into its representations, by means of the synthetic unity of the manifold of intuition in general.... (CPR A79/B loS) The importance of this paragraph is, however, more than equaled by its difficulties, which center on the question of how the function which operates by means of analytical unity can be the same as one that operates by means of the synthetic unity of the manifold of intuition in general. Put shortly, the problem is this. If the functions are really the same, then how do we distinguish at all between analytic and synthetic operations? But if they are different, then how can these forms of judgment serve as a clue for the discovery of the categories? ' Immanuel Kant, Critiqueof Pure Reason, trans. Norman KempSmith (London: Macmillan and Co., Ltd., 1963).Hereafter CPR. [89] 9~ JOURNAL OF THE HISTORY OF PHILOSOPHY 28:1 JANUARY 1990 The results of this dilemma which can be observed in the literature are not surprising: commentators tend to grasp one horn or the other. They either emphasize the difference between analysis and synthesis, and reject or dilute the claims as to sameness of function; or they take seriously Kant's argument concerning sameness of functions, and try to minimize the difference between analysis and synthesis. The major twentieth-century representant of the former approach is Kemp Smith," and of the latter, Paton. 3 This latter approach has found a formidable contemporary champion in the person of Henry Allison. By Allison's own admission,4 however, his position on this controversial topic was suggested (in part) by arguments first put forward over fifty years ago by Klaus Reich in a most remarkable book entitled Die Volls~ndigkeit der Kantischen Urteilstafel, 5 a book, by the way, also greatly admired by Paton. 6 In the first section of this paper I will try to show that Reich's arguments are rather more subtle than Allison apparently takes them to be, and that Reich is one commentator who attempts to go between the horns of the dilemma described above, and who essays an interpretation of our crucial paragraph that unifies its seemingly divergent tendencies. In the second section of the paper I will introduce some interpretive elements of my own. 2. Let us begin by reacquainting ourselves with Kant's notion of analytical unity, one aspect of this debate which is not particularly controversial and is largely agreed upon by all parties. For Kant, analytical unity is the sort of unity achieved by all general concepts (conceptus communes) insofar as they abstract from all differences that subsist between the objects under them, or the lower concepts subordinated to them. 7 A general concept unifies these objects or concepts by means of a common mark or set of marks. Thus Kant's example at CPR A69/B94 of the unification of bodies under the concepts 'body' and 'divisible' is a perfectly representative instance of unification via analytical unity, as the function upon which such concepts "rest." Let us note that the " Norman KempSmith,A CommentarytoKant's "Cr/t~rueofPureReason"(NewYork:HumanitiesPress, 196~). 3 H.J. Paton, Kant's MetaphysicofExperience, 2 vols.(London:George Allenand Unwin,Ltd., 1936). 4 Henry Allison,Kant's TranscendentalIdealum (NewHaven:YaleUniversityPress, 1983), 144 n. 3o. Hereafter KTI. 5 KlausReich,Die Vollst~ndigkeitderKantischenUrteilstafel,3rd. ed. (Hamburg: Meiner, 1986). Hereafter VKU. 6 Paton, Kant's Metaphysic, 1:302. Kant, we should note, does not makethis important logicaldistinctionbetweensubordination... (shrink)

This chapter considers Kant's relation to Hume as Kant himself understood it when he wrote the Critique of Pure Reason and the Prolegomena. It first seeks to refine the question of Kant's relation to Hume's skepticism, and it then considers the evidence for Kant's attitude toward Hume in three works: the A Critique, Prolegomena, and B Critique. It argues that in the A Critique Kant viewed skepticism positively, as a necessary reaction to dogmatism and a spur toward critique. In his (...) initial statement of the critical philosophy Kant treated Hume as an ally in curbing dogmatism, but one who stopped short of what was really needed: a full critique of reason, to establish the boundaries of metaphysical cognition. Kant found fault with Hume's analyses of cognition and experience, and specifically his failure to see the crucial importance of synthetic a priori cognition in metaphysics. In particular, he held that Hume's empiricist account of cognition could neither explain the synthetic a priori cognition actually found in mathematics and natural science, nor provide a principled account of the limits on what can be known--and what can be thought--through the pure concepts of the understanding. According to Kant, Hume therefore failed in his attempt to determine the limits of metaphysics, whereas he was able to succeed because his transcendental philosophy provided a thorough account of cognition, its structure and limits. In the Prolegomena and the B Critique Kant distinguished his position more sharply from Hume's. He also adopted a more negative attitude toward "skeptical idealism" than before; but he attributed such skepticism to Descartes, not Hume. Prior to the B Critique Kant did not see Hume as attacking natural science or ordinary cognition. In none of the three works was Kant's main aim to "answer the skeptic." His primary aim was to firmly establish the boundary of metaphysics, by discovering the elements of human cognition and fixing its proper domain. His purported discoveries about the limits of metaphysical cognition meant that the traditional objects of metaphysical knowledge, God, the soul, and the world as it is in itself, are unknowable, hence that traditional metaphysics itself is impossible. Besides settling the possibility or impossibility of metaphysics, his findings would also prevent the illegitimate extension of principles of sensibility to God and the noumenal self, an extension that would threaten the metaphysics of morals by incorrectly denying the thinkability of noumenal freedom, and that might otherwise lead to "materialism, fatalism, atheism, and freethinking unbelief" (B xxxiv). (shrink)

I argue that Kant’s distinction between the cognitive roles of sensibility and understanding raises a question concerning the conditions necessary for objective representation. I distinguish two opposing interpretive positions—viz. Intellectualism and Sensibilism. According to Intellectualism all objective representation depends, at least in part, on the unifying synthetic activity of the mind. In contrast, Sensibilism argues that at least some forms of objective representation, specifically intuitions, do not require synthesis. I argue that there are deep reasons for thinking that Intellectualism (...) is incompatible with Kant's view as expressed in the Transcendental Aesthetic. We can better see how Kant’s arguments in the first Critique may be integrated, I suggest, by examining his notion of the 'unity' [Einheit] of a representation. I articulate two distinct ways in which a representation may possess unity and claim that we can use these notions to integrate Kant’s arguments in the Aesthetic and the Transcendental Deduction without compromising the core claims of either Sensibilism or Intellectualism—that intuition is a form of objective representation independent of synthesis, and that the kind of objective representations that ground scientific knowledge of the world require synthesis by the categories. (shrink)

Probabilistic models have started to replace classical logic as the standard reference paradigm in human deductive reasoning. Mental probability logic emphasizes general principles where human reasoning deviates from classical logic, but agrees with a probabilistic approach (like nonmonotonicity or the conditional event interpretation of conditionals). -/- This contribution consists of two parts. In the first part we discuss general features of reasoning systems including consequence relations, how uncertainty may enter argument forms, probability intervals, and probabilistic informativeness. (...) These concepts are of central importance for the psychological task analysis. In the second part we report new experimental data on the paradoxes of the material conditional, the probabilistic modus ponens, the complement task, and data on the probabilistic truth table task. The results of the experiments provide evidence for the hypothesis that people represent indicative conditionals by conditional probability assertions. (shrink)

Lance Rips describes a unified theory of natural deductive reasoning and fashions a working model of deduction, with strong experimental support, that is capable of playing a central role in mental life.

In section 1, I develop epistemic communism, my view of the function of epistemically evaluative terms such as ‘rational’. The function is to support the coordination of our belief-forming rules, which in turn supports the reliable acquisition of beliefs through testimony. This view is motivated by the existence of valid inferences that we hesitate to call rational. I defend the view against the worry that it fails to account for a function of evaluations within first-personal deliberation. In the rest of (...) the paper, I then argue, on the basis of epistemic communism, for a view about rationality itself. I set up the argument in section 2 by saying what a theory of rational deduction is supposed to do. I claim that such a theory would provide a necessary, sufficient, and explanatorily unifying condition for being a rational rule for inferring deductive consequences. I argue in section 3 that, given epistemic communism and the conventionality that it entails, there is no such theory. Nothing explains why certain rules for deductive reasoning are rational. (shrink)

Originally published in 1982, this was an extensive and up-to-date review of research into the psychology of deductive reasoning, Jonathan Evans presents an alternative theoretical framework to the rationalist approach which had dominated much of the published work in this field at the time. The review falls into three sections. The first is concerned with elementary reasoning tasks, in which response latency is the prime measure of interest. The second and third sections are concerned with syllogistic and (...) propositional reasoning respectively, in which interest has focused on the explanation of frequently observed logical errors. In an extended discussion it is argued that reasoning processes are content specific, and give little indication of the operation of any underlying system of logical competence. Finally, a dual process theory of reasoning, with broad implications and connections with other fields of psychology, is elaborated and assessed in the light of recent evidence. (shrink)

Deductive reasoning is the kind of reasoning in which, roughly, the truth of the input propositions (the premises) logically guarantees the truth of the output proposition (the conclusion), provided that no mistake has been made in the reasoning. The premises may be propositions that the reasoner believes or assumptions that the reasoner is exploring. Deductive reasoning contrasts with inductive reasoning, the kind of reasoning in which the truth of the premises need not (...) guarantee the truth of the conclusion. (shrink)

This paper describes a cubic water tank equipped with a movable partition receiving various amounts of liquid used to represent joint probability distributions. This device is applied to the investigation of deductive inferences under uncertainty. The analogy is exploited to determine by qualitative reasoning the limits in probability of the conclusion of twenty basic deductive arguments (such as Modus Ponens, And-introduction, Contraposition, etc.) often used as benchmark problems by the various theoretical approaches to reasoning under uncertainty. (...) The probability bounds imposed by the premises on the conclusion are derived on the basis of a few trivial principles such as "a part of the tank cannot contain more liquid than its capacity allows", or "if a part is empty, the other part contains all the liquid". This stems from the equivalence between the physical constraints imposed by the capacity of the tank and its subdivisions on the volumes of liquid, and the axioms and rules of probability. The device materializes de Finetti's coherence approach to probability. It also suggests a physical counterpart of Dutch book arguments to assess individuals' rationality in probability judgments in the sense that individuals whose degrees of belief in a conclusion are out of the bounds of coherence intervals would commit themselves to executing physically impossible tasks. (shrink)

In the first part of this paper I contend that Michael Dummett’s works contain a distinction between analytic and synthetic (logical) deductions. Dummett does not use Kant’s terminology. Nevertheless, based on general considerations about theories of meaning, Dummett shows how one can distinguish between deductions whose validity is recognised by merely grasping the concepts and deductions whose validity can be recognised only by “going beyond the concepts”, as Kant wrote. The latter are synthetic deductions, through which we can (...) increase our knowledge. A special merit of Dummett’s distinction is its theoretical flexibility and generality. He does not propose a single clear-cut distinction between analytic and synthetic deductions; rather in his works we find an indication of how to draw a distinction once a theory of meaning is adopted. In the second part of the paper I consider possible developments within an inferentialist theory of meaning and draw some conclusions concerning the fallibility of deductions. (shrink)

Using the matching bias example, the aim of the present studies was to show that adults' reasoning biases are due to faulty executive inhibition programming. In the first study, the subjects were trained on Wason's classical card selection task; half were given training in how to inhibit the perceptual matching bias (experimental group) and half in logic without the inhibition component (control group). On the pre- and post-tests, their performance was assessed on the Evans conditional rule falsification task (with (...) a negation in the antecedent of the rule), a task that also involves matching bias. In addition, subjects were tested for perceptual field dependence/independence using the Embedded Figures Test. The results brought out a specific inhibition training effect, as well as a clear-cut relationship in the experimental group between receptiveness to training and perceptual field independence. In the second study, the training paradigm was the same except that on the pre- and post-tests, the negation was in the consequent of the conditional rule (in this case, the perceptual matching response corresponds to the logical response). The subjects succeeded on the pre-test, and the matching-bias inhibition training had a negative effect on post-test performance. This specific negative priming effect confirms the inhibitory impact of our experimental training and outlines the dissociation of inhibition and logical components. (shrink)

The role and nature of imagination in Kant's Critique of Pure Reason is intensively examined. In addition, the text of Kant's Anthropology from a Pragmatic Point of View will also be considered because it helps illustrate this issue. Imagination is the fundamental power of the mind responsible for any act of forming and putting together representations. A new interpretation of imagination in Kant is given which recognizes its necessary roles as the factor responsible for producing space and time, as an (...) essential component in perception, as the mediator of concepts and intuitions, and as the synthesizing agent which groups together representations into categories. ;The work is divided basically into two parts. The first part looks at the imagination in the Transcendental Aesthetic. It will be shown that space and time themselves are products of imagination. As pure and a priori intuitions space and time are objects of thought and thus are conditioned by the synthetic power of imagination. Moreover, as forms of intuitions space and time are also conditioned by imagination; hence, imagination is a necessary factor in spatial and temporal perception. ;The second part of the thesis concerns the role of imagination in the Transcendental Analytic. Here the role of the imagination is more pervasive. In the Metaphysical Deduction the thesis argues that the imagination is responsible for uniting representations into twelve categories which are the conditions of thinking in general. Therefore the categories themselves owe their origins to imagination. This interpretation hinges on Kant's distinction between transcendental and general logic, which the thesis will discuss in detail. In the Transcendental Deduction the imagination is responsible for taking up representations in such a way that results in their belonging to a single framework of consciousness, thus showing that the categories apply to a posteriori representations. In the Schematism the imagination is necessary in forming the schemata, which join together concepts and intuitions so that both empirical and transcendental judgments are produced. Finally, a critique of Heidegger's idea on imagination as the "common root" of sensibility and understanding will be offered. (shrink)

Recent studies have shown that deductive reasoning skills are related to mathematical abilities. Nevertheless, so far the links between mathematical abilities and these two forms of deductive inference have not been investigated in a single study. It is also unclear whether these inference forms are related to both basic maths skills and mathematical reasoning, and whether these relationships still hold if the effects of fluid intelligence are controlled. We conducted a study with 87 adult participants. The (...) results showed that transitive reasoning skills were related to performance on a number line task, and conditional inferences were related to arithmetic skills. Additionally, both types of deductive inference were related to mathematical reasoning skills, although transitive and conditional reasoning ability were unrelated. Our results also highlighted the important role that ordering abilities play in mathematical reasoning, extending findings regarding the role of ordering abilities in basic maths skills. These results have implications for the theories of mathematical and deductive reasoning, and they could inspire the development of novel educational interventions. (shrink)

How we read Kant's Critique of Pure Reason has a huge influence on how convincing we find the parts of which it is composed. This thesis will argue that by taking its arguments and concepts in isolation we neglect the unifying architectonic method that Kant employed. Understanding this text as a response to a single problem, that of the possibility of synthetic a priori judgement, will allow us to evaluate it more fully. We will explore Kant's attempts to relate (...) the a priori and the synthetic in the Introduction, Metaphysical Deduction and Analytic of Principles of the Critique of Pure Reason. Having developed this reading at length we will be able to reassess Kant's relation to the work of Gilles Deleuze. Deleuze's critique of Kant and his tendency to make selective use of his work has so far characterised their relations. However, by reading Kant's Critique of Pure Reason in terms of its unifying method we will open up a new means of relating these two thinkers. Whilst Deleuze rejects many key Kantian concerns and concepts he embraces his methodological concern with the ability of problems to unify our thought. The problem-setting and forms of argument that emerge within Kant's architectonic method will be related to Deleuze's account of experience. This thesis will contribute to both Kant and Deleuze studies on the basis of the reading of the Critique of Pure Reason it will present. By showing how Kant's text is to be read as a whole we will be able to challenge the conclusion that the arguments he makes ultimately rely upon a notion of 'subjective origin'. The problem of accounting for 'the actual' through its relation to 'the virtual' in Deleuze's thought will be re-assessed on the basis of his newly established relation with Kant. Understanding Kant's method in the Critique of Pure Reason will be shown to strengthen both his own account of experience and that offered by Deleuze. (shrink)

The paper aims at the rehabilitation of deductive reasoning. As a paradigm of reliable reasoning, it should be applicable in every confirmation context. In particular, it should transmit inductive justification, so that if D justifies a hypothesis H, then D also justifies all deductive conclusions from H. Nevertheless, most current philosophers of science reject such a transmission principle as false. They argue against it by providing apparent counter-examples and also by showing that it is incompatible with (...) common confirmation theories such as HD-confirmation and Bayesianism. I argue in the opposite direction that we should stick to the transmission principle and revise instead our justification theories towards more cautious justification procedures that respect the transmission principle. This will avoid further paradoxes of these theories and, in particular, will enable us to apply our confirmed hypotheses to new situations in a well-founded way. (shrink)

(1994). Inductive reasoning, deductive reasoning and mental models. International Studies in the Philosophy of Science: Vol. 8, No. 1, pp. 65-67. doi: 10.1080/02698599408573483.

While inductive and deductive reasoning are considered distinct logical and psychological processes, little is known about their respective neural basis. To address this issue we scanned 16 subjects with fMRI, using an event-related design, while they engaged in inductive and deductive reasoning tasks. Both types of reasoning were characterized by activation of left lateral prefrontal and bilateral dorsal frontal, parietal, and occipital cortices. Neural responses unique to each type of reasoning determined from the (...) class='Hi'>Reasoning Type by Task interaction indicated greater involvement of left inferior frontal gyrus in deduction than induction, while left dorsolateral prefrontal gyrus showed greater activity during induction than deduction. This pattern suggests a dissociation within prefrontal cortex for deductive and inductive reasoning. (shrink)

lt is hypothesized that people use formally incorrect deductive procedures, and this is sometimes advisable. The particular "prototypicaiity heuristic" investigated is: to determine validity of a proof, (a) work out an example, and (b) pick a "good" rather than arbitrary example. An interaction was predicted betv;een validity of inference and proto-typicality of example. Experiment 1, although quite sensitive to "calibration' variables, does not reveal the interaction in reaction times. However, Experiment 2, in which subjects' time was limited, seems to (...) elicit the interaction in subjects' first-trial confidence judgments; the explanation proposed is that subjects then decide they must shift to a "quick and dirty" heuristic. Experiment 3 provides some preliminary evidence that subjects' 'metaheuristic". (shrink)

Current conceptions of the nature of human reasoning make it no longer tenable to assess children's inference by reference to the norms of logical inference. Alternatively, the complexity of the mental models employed in children's inferences can be analysed. This approach is applied to transitive inference, class inclusion, categorical induction, theory of mind, oddity, categorical syllogisms, analogy, and reasoning deficits. It is argued that a coherent account of children's reasoning emerges in that there is correspondence between tasks (...) at the same level of complexity across different domains, and that the inferences of younger children, while impressive and important, are consistently simpler than those of older children. (shrink)

Contributors to this volume present methodological foundations for deductive modeling in policy analysis, applications to particular areas of public policy, and applications to the institutional framework within which particular policies are chosen.

From the point of view of proof-theoretic semantics, it is argued that the sequent calculus with introduction rules on the assertion and on the assumption side represents deductive reasoning more appropriately than natural deduction. In taking consequence to be conceptually prior to truth, it can cope with non-well-founded phenomena such as contradictory reasoning. The fact that, in its typed variant, the sequent calculus has an explicit and separable substitution schema in form of the cut rule, is seen (...) as a crucial advantage over natural deduction, where substitution is built into the general framework. (shrink)

I address a type of circularity threat that arises for the view that we employ general basic logical principles in deductive reasoning. This type of threat has been used to argue that whatever knowing such principles is, it cannot be a fully cognitive or propositional state, otherwise deductive reasoning would not be possible. I look at two versions of the circularity threat and answer them in a way that both challenges the view that we need to (...) apply general logical principles in deductive reasoning and defuses the threat to a cognitivist account of knowing basic logical principles. (shrink)