This article summarizes how logic has been seen in relation to philosophy and to the sciences based on some of the major developments in the history of logic itself.
The Greeks
Aristotle divided up the areas of philosophical knowledge into theoretical (mathematics, philosophy of nature, metaphysics), practical (ethics, political philosophy), and productive (Art, Rhetoric), but logic does not seem to have any place of its own in this division. There is only one passage in the Rhetoric 1359 b10 where Aristotle speaks of logic as the ‘analytic science’. In general, however, logic for him was part of a general ‘organon’ (instrument) that should be learned first (Metaphysics, 995a12) in order for the scholar to become competent for the study of any of the real sciences. The reason that logic should be learned first was that it teaches the method that is to be observed if one is to acquire a science, and one cannot simultaneously learn a method and use it. Indeed, unless we first know what the logical demands of a science are, we may not possess the common methodology or procedure that must be followed if the science is to be acquired.
In later divisions of the sciences, by contrast, logic most frequently is included among the philosophical sciences rather than regarded as a preparatory tool. Thus after Aristotle, the Stoics would divide the sciences into physics, ethics, and logic or dialectic.
Kant
It is this Hellenistic division that was later taken up and revised by Immanuel Kant in his famous Groundwork of the Metaphysics of Morals, though Kant otherwise regarded logic as “finished and complete” since the time of Aristotle (see Critique of Pure Reason, B viii). According to Kant’s revised division of the philosophical disciplines in the Groundwork, logic simply is ‘formal’ philosophy in the sense that it deals only with the form of understanding, as opposed to material philosophy (physics/doctrine of nature and ethics/doctrine of morals), which is concerned with determinate objects and with the laws governing them. However, Kant did not appear to regard the systematic study of logic as necessary for the study of other parts of philosophy, as becomes clear from the structure of the Critique of Pure Reason, in which Kant starts out dealing with a transcendental exposition of space and time as conditions of the possibility of experience, and only then moves on to the transcendental deduction of the categories and to a discussion of formal logic.
20th Century Developments and Reassessments
In the 20th century, Aristotle's reputation as a logician underwent two remarkable reversals. First, the rise of modern formal logic following the work of Gottlob Frege and Bertrand Russell brought with it a recognition of the many serious limitations of Aristotle's logic. Today, very few would try to maintain that it is adequate as a basis for understanding science, mathematics, or even everyday reasoning. At the same time, however, scholars trained in modern formal techniques have come to view Aristotle with new respect, not so much for the correctness of his results as for the remarkable similarity in spirit between much of his work and modern logic. According to this revisionist account of Aristotle’s logic, his primary goal was not to offer a mere practical guide to argumentation but to study the properties of inferential systems themselves (see, for instance: Lear, Jonathan. 1980. Aristotle and Logical Theory. Cambridge University Press). And insofar as he did have this goal, his treatment of logic arguably was in fact a lot more ‘scientific’ than Kant’s, almost as much as contemporary logic is.
