KANT'S THEORY OF JUDGMENT

INTRODUCTION
Theories of judgment bring together fundamental issues in semantics, logic, philosophical psychology, epistemology, and action theory: indeed, the notion of judgment is central to any theory of human rationality. But Kant's theory of judgment differs sharply from many other theories of judgment, both traditional and contemporary, in three ways: (1) by taking the capacity for judgment to be the central cognitive faculty of the human mind, (2) by insisting on the semantic, logical, psychological, epistemic, and practical priority of the propositional content of a judgment, and (3) by systematically embedding judgment within the metaphysics of transcendental idealism . Several serious problems are generated by the interplay of the first two factors with the third. This in turn suggests that the other two parts of Kant's theory of judgment can be logically detached from his transcendental idealism and defended independently of it.


VARIETIES OF JUDGEMENT
In the Prolegomena to any Future Metaphysic (1783) Kant presented the central themes of the firstCritique in a somewhat different manner, starting from instances in which we do appear to have achieved knowledge and asking under what conditions each case becomes possible. So he began by carefully drawing a pair of crucial distinctions among the judgments we do actually make.


The first distinction separates a priori from a posteriori judgments by reference to the origin of our knowledge of them. A priori judgments are based upon reason alone, independently of all sensory experience, and therefore apply with strict universality. A posteriori judgments, on the other hand, must be grounded upon experience and are consequently limited and uncertain in their application to specific cases. Thus, this distinction also marks the difference traditionally noted in logic between necessary and contingent truths.


But Kant also made a less familiar distinction between analytic and synthetic judgments, according to the information conveyed as their content. Analytic judgments are those whose predicates are wholly contained in their subjects; since they add nothing to our concept of the subject, such judgments are purely explicative and can be deduced from the principle of non-contradiction. Synthetic judgments, on the other hand, are those whose predicates are wholly distinct from their subjects, to which they must be shown to relate because of some real connection external to the concepts themselves. Hence, synthetic judgments are genuinely informative but require justification by reference to some outside principle.


Kant supposed that previous philosophers had failed to differentiate properly between these two distinctions. Both Leibniz and Hume had made just one distinction, between matters of fact based on sensory experience and the uninformative truths of pure reason. In fact, Kant held, the two distinctions are not entirely coextensive; we need at least to consider all four of their logically possible combinations:

• Analytic a posteriori judgments cannot arise, since there is never any need to appeal to experience in support of a purely explicative assertion.
• Synthetic a posteriori judgments are the relatively uncontroversial matters of fact we come to know by means of our sensory experience (though Wolff had tried to derive even these from the principle of contradiction).
• Analytic a priori judgments, everyone agrees, include all merely logical truths and straightforward matters of definition; they are necessarily true.
• Synthetic a priori judgments are the crucial case, since only they could provide new information that is necessarily true. But neither Leibniz nor Hume considered the possibility of any such case.

Synthetic a priori proposition
In logic, a proposition the predicate of which is not logically or analytically contained in the subject—i.e., synthetic—and the truth of which is verifiable independently of experience—i.e., a priori. Thus the proposition “Some bodies are heavy” is synthetic because the idea of heaviness is not necessarily contained in that of bodies. On the other hand, the proposition “All husbands are male” is analytic because the idea of maleness is already contained in that of husband. In general the truth or falsity of synthetic statements is proved only by whether or not they conform to the way the world is and not by virtue of the meaning of the words they contain. Synthetic a priori knowledge is central to the thought of Immanuel Kant, who argued that some such a priori concepts are presupposed by the very possibility of experience.