§ 8. The theory of the syllogism, laid down in the preceding pages, has obtained, among other important adhesions, three of peculiar value; those of Sir John Herschel,[10] Dr. Whewell[11] and Mr. Bailey;[12] Sir John Herschel considering the doctrine, though not strictly "a discovery,"[13] to be "one of the greatest steps which have yet been made in the philosophy of Logic." "When we consider" (to quote the further words of the same authority) "the inveteracy of the habits and prejudices which it has cast to the winds," there is no cause for misgiving in the fact that other thinkers, no less entitled to consideration, have formed a very different estimate of it. Their principal objection cannot be better or more succinctly stated than by borrowing a sentence from Archbishop Whately.[14] "In every case where an inference is drawn from Induction (unless that name is to be given to a mere random guess without any grounds at all) we must form a judgment that the instance or instances adduced are _sufficient_ to authorize the conclusion; that it is _allowable_ to take these instances as a sample warranting an inference respecting the whole class;" and the expression of this judgment in words (it has been said by several of my critics) _is_ the major premise. I quite admit that the major is an affirmation of the sufficiency of the evidence on which the conclusion rests. That it is so, is the very essence of my own theory. And whoever admits that the major premise is _only_ this, adopts the theory in its essentials. But I cannot concede that this recognition of the sufficiency of the evidence--that is, of the correctness of the induction--is a part of the induction itself; unless we ought to say that it is a part of everything we do, to satisfy ourselves that it has been done rightly. We conclude from known instances to unknown by the impulse of the generalizing propensity; and (until after a considerable amount of practice and mental discipline) the question of the sufficiency of the evidence is only raised by a retrospective act, turning back upon our own footsteps, and examining whether we were warranted in doing what we have already done. To speak of this reflex operation as part of the original one, requiring to be expressed in words in order that the verbal formula may correctly represent the psychological process, appears to me false psychology.[15] We review our syllogistic as well as our inductive processes, and recognise that they have been correctly performed; but logicians do not add a third premise to the syllogism, to express this act of recognition. A careful copyist verifies his transcript by collating it with the original; and if no error appears, he recognises that the transcript has been correctly made. But we do not call the examination of the copy a part of the act of copying.