Kant: Political Writings

A collection of rules, even of practical rules, is termed a theory if the rules concerned are envisaged as principles of a fairly general nature, and if they are abstracted from numerous conditions which, nonetheless, necessarily influence their practical application. Conversely, not all activities are called practice, but only those realisations of a particular purpose which are considered to comply with certain generally conceived principles of procedure.

It is obvious that no matter how complete the theory may be, a middle term is required between theory and practice, providing a link and a transition from one to the other. For a concept of the understanding, which contains the general rule, must be supplemented by an act of judgement whereby the practitioner distinguishes instances where the rule applies from those where it does not. And since rules cannot in turn be provided on every occasion to direct the judgement in subsuming each instance under the previous rule (for this would involve an infinité regress), theoreticians will be found who can never in all their lives become practical, since they lack judgement. There are, for example, doctors or lawyers who did well during their schooling but who do not know how to act when asked to give advice. But even where a natural talent for judgement is present, there may still be a lack of premises. In other words, the theory may be incomplete, and can perhaps be perfected only by future experiments and experiences from which the newly qualified doctor, agriculturalist or economist can and ought to abstract new rules for himself to complete his theory. It is therefore not the fault of the theory if it is of little practical use in such cases. The fault is that there is not enough theory; the person concerned ought to have learnt from experience. What he learnt from experience might well be true theory, even if he were unable to impart it to others and to expound it as a teacher in systematic general propositions, and were consequently unable to claim the title of a theoretical physician, agriculturalist or the like. Thus no-one can pretend to be practically versed in a branch of knowledge and yet treat theory with scorn, without exposing the fact that he is an ignoramus in his subject.