This paper considers the question of whether Mill's account of the nature and justificatory foundations of deductive logic is psychologistic. Logical psychologism asserts the dependency of logic on psychology. Frequently, this dependency arises as a result of a metaphysical thesis asserting the psychological nature of the subject matter of logic. A study of Mill's System of Logic and his Examination reveals that Mill held an equivocal view of the subject matter of logic, sometimes treating it as a set of psychological (...) processes and at other times as the objects of those processes. The consequences of each of these views upon the justificatory foundations of logic are explored. The paper concludes that, despite his providing logic with a prescriptive function, and despite his avoidance of conceptualism, Mill's theory fails to provide deductive logic with a justificatory foundation that is independent of psychology. (shrink)

Many contemporary logicians acknowledge a plurality of logical theories and accept that theory choice is in part motivated by logical evidence. However, just as there is no agreement on logical theories, there is also no consensus on what constitutes logical evidence. In this paper, I outline Jean Piaget’s psychological theory of reasoning and show how he used it to diagnose and solve one of the paradoxes of material implication. I assess Piaget’s use of psychology as a source of evidence for (...) logical theory in light of reservations raised by psychologism, and I highlight some ramifications for exceptionalism and anti-exceptionalism about logic by considering his use of psychology as logical evidence in the framework of genetic epistemology, Piaget’s research programme. I conclude that Piaget’s psychological theory of reasoning not only plausibly serves as a source of evidence for logical theory but also makes a strong case for anti-exceptionalism about logic. (shrink)

Intentionality may be dealt with in two different ways: either ontologically, as an ordinary relation to some extraordinary objects, or epistemologically, as an extraordinary relation to some ordinary objects. This paper endorses the epistemological view in order to provide a model of semiotic intentionality defined as the meaning-and-cognizing process that constitutes to power of the mind to be about something on the basis of a semiotic system. After a short introduction that presents the components of semiotic intentionality (viz. sign, act, (...) content, referent) along with their division into an intending and a fulfilling side (Sect. 1), the first main part of the paper analyzes semiotic intentionality at its primary level (a.k.a. 'concrete intentionality') as a real and subjective relation between meaning-intending and meaning-fulfilling acts grounded in the manipulation of some semiotic system (Sect. 2). Then, building on such concrete intentionality, the second main part of the paper analyzes semiotic intentionality at its secondary level (a.k.a. 'abstract intentionality') as an ideal and objective relation between intentional and fulfillment contents, which in turn: (i) proceed from an abstraction performed on the intending and fulfilling acts, respectively, and (ii) retroactively categorize the intending and fulfilling acts, respectively (Sect. 3). Finally, from this combination of an act-based conception of content with a presentationalist account of intentionality, the conclusion of this paper produces the intended model of semiotic intentionality in such a way that knowledge and truth are then respectively defined in it as the subjective correspondence between the two acts of concrete intentionality and as the objective correspondence between the two contents of abstract intentionality (Sect. 4). (shrink)