(f) So long as the logician regards his premisses not as hypotheses to be tested, but as established truths, he must condemn the Syllogism as a formal fallacy. It is inevitably a petitio principii. If the argument 'All men are mortal; Smith is a man, therefore Smith is mortal,' means that we know, before drawing our inference, that literally all men are mortal, we must already have discovered that Smith is mortal; if we did not know beforehand that Smith is mortal, we were not justified in stating that all men are mortal. Nor is it an escape to interpret 'All men are mortal' to mean that immortals are excluded from 'man' by definition. For then the question is merely begged in the minor premiss. That 'Smith is a man' cannot be asserted without assuming that he is mortal. If, lastly, 'All men are mortal' be taken to state a law of nature conjoining inseparably mortality and humanity, the logician either already knows that Smith is rightly classed under the species 'man,' and so subject to its mortality, or else he assumes this. But how does he know Smith is not like Elijah or Tithonus, a peculiar case, to which for some reason the law does not apply? Will he declare it to be 'intuitively certain' that whatever is called, or looks like, a case of a 'law' ipso facto becomes one?
The logician's analysis of reasoning, then, breaks down. In whichever way he interprets the Syllogism it is revealed as either a superfluity or a fallacy: it is never a 'formally valid inference' that can compel assent. But common sense is undismayed by the pragmatist's discovery that if the Syllogism is to have any sense its premisses must be taken as disputable; for, unlike Formal Logic, it has perceived that men do not reason about what they think they know for certain, but about matters in dispute.
4. It is not necessary to dwell at length on the futility of the formal notion of Induction. Formal Induction presupposes that enough particular instances have been collected to establish a general rule; but in actual practice inductions always repose, not on indiscriminate observation, but on a selection of relevant instances, and never claim to be based upon an exhaustive knowledge of particulars. Hence in form the most satisfactory induction is always incomplete, and differs in no wise from a bad one. 'All bodies fall to the ground' is an induction which has worked. 'All swans are white' broke down when black swans were discovered in Australia. The validity of an induction, then, is not a question of form.
The necessity for such selection no intellectualist theory of Induction has understood. All have aimed at exhaustiveness, and imagined that if it could be attained, inductive reasoning would be rendered sound, and not impossible. Their ideal 'cause' was the totality of reality, identified with its 'effect,' in a meaningless tautology. Nothing but voluntarism can enable logicians to see that our actual procedure in knowing is the reverse of this, that causal explanation is the analysis of a continuum, and that 'phenomena,' 'events,' 'effects,' and 'causes' are all creations of our selective attention; that in selecting them we run a risk of analyzing falsely, and that if we do, our 'inductions' will be worthless. But whether they are right or wrong, valuable or not, real reasoning from 'facts' can never be a 'formally valid' process.
We are thus brought to see the hollowness of the contention that 'Pure Reason' can ignore its psychological context and dehumanize itself. A thought, to be thought at all, must seem worth thinking to someone, it must convey the meaning he intends, it must be true in his eyes and relevant to his purposes in the situation in which it arises—i.e., it must have a motive, a value, a meaning, a purpose, a context, and be selected from a greater whole for its relevance to these. None of these features does intellectualist logic deign to recognize. For if truth is absolute and not relative, it is all or nothing. Yet no actual thinking has such transcendent aims. It is content with selections relative to a concrete situation. If it were permissible to diversify a debate—e.g., about the authorship of the Odyssey—by an irruption of undisputed truths—e.g., a recitation of the multiplication table—how would it be possible to distinguish a philosopher from a lunatic?
Formal Logic is either a perennial source of errors about real thinking, or at best an aimless dissection of a caput mortuum—i.e., of the verbal husks of dead thoughts, whose value Formal Logic could neither establish nor apprehend, A real Logic, therefore, would most anxiously avoid all the initial abstractions which have reduced Formal Logic to such impotence, and would abandon the insane attempt to eliminate the thinker from the theory of thought.
FOOTNOTES:
[F] The descriptive science of thought, in its concrete actuality in different minds.
[G] The most popular contribution which Oxford makes just now to the theory of Error is, 'A judgment which is erroneous is not really a judgment.' So when a professor 'judges' he is infallible—by definition!