'It gives a very favourable idea of Sir W. Hamilton's sincerity and devotion to truth (remarks Mr Mill, p. 247), that he should have drawn from obscurity, and made generally known, two cases so unfavourable to his own opinions.'
We think this remark perfectly just; and we would point out besides, in appreciating Sir W. Hamilton's merits, that his appetite for facts was useful to philosophy, as well as his appetite for speculation. But the person whose usefulness to philosophy we prefer to bring into the foreground, is Platner himself. He spent three weeks in patient examination of this blind man, and the tenor of his report proves that his sagacity in interpreting facts was equal to his patience in collecting them. The rarity of all such careful and premeditated observation of the facts of mind, appears to us one main reason why (what Mr Mill calls) the psychological theory finds so little acceptance; and why those who maintain that what now seems a mental integer was once a multiplicity of separate mental fragments, can describe the antecedent steps of the change only as a latens processus, which the reader never fully understands, and often will not admit. Every man's mind is gradually built up from infancy to maturity; the process is always going on before our eyes, yet the stages of it—especially the earliest stages, the most pregnant with instruction—are never studied and put on record by observers trained in inductive logic, knowing beforehand what they ought to look for as the sine quâ non for proving or disproving any proposed theory. Such cases as that cited by Platner—cases of one marked congenital defect of sense, enabling us to apply the Method of Difference—are always within reach; but few Platners are found to scrutinize and record them. Historians of science describe to us the laborious and multiplied observations, and the elaborate precaution for ensuring accuracy of observation, which recent chemical and physical inquirers have found indispensable for the establishment of their results. We cannot, therefore, be surprised that mental philosophers, dealing with facts even more obscure, and careless about enlarging, varying, authenticating their records of particular facts, should have had little success in establishing any results at all.
But if even those, who adopt the psychological theory, have been remiss in the observation of particular mental facts,—those who deny the theory have been far more than remiss; they have been blind to obvious facts contradicting the principles which they lay down. Mr Mill, in chap, xiv., deals with this denial, common to Mr Mansel with Sir W. Hamilton. That philosophers so eminent as both of them should declare confidently—'what I cannot but think must be à priori, or original to thought; it cannot be engendered by experience upon custom' (p. 264)—appears to us as extraordinary as it does to Mr Mill. Though no one ever surpassed Sir W. Hamilton in large acquaintance with the actual diversities of human belief, and human incapacities of believing—yet he never seems to have thought of bringing this acquaintance into account, when he assured the students in his lecture-room, that custom, experience, indissoluble association, were altogether insufficient to engender a felt necessity of believing. Such forgetfulness of well-known mental facts cannot be reproached to the advocates of the psychological theory.
In chap. xv. Mr Mill examines Sir W. Hamilton's doctrine on unconscious mental modifications. He points out the confused manner in which Sir W. Hamilton has conceived mental latency, as well as the inconclusive character of the reasoning whereby he refutes the following doctrine of Dugald Stewart—That in the most rapid trains of association, each separate item must have been successively present to consciousness, though for a time too short to leave any memory. Sir W. Hamilton thinks that the separate items may pass, and often do pass, unconsciously; which opinion Mr Mill also, though not approving his reasons, is inclined to adopt.
'I am myself inclined (p. 285) to admit unconscious mental modifications, in the only sense in which I can attach any very distinct meaning to them—namely, unconscious modifications of the nerves. It may well be believed that the apparently suppressed links in a chain of association, those which Sir W. Hamilton considers as latent, really are so: that they are not even momentarily felt, the chain of causation being continued only physically—by one organic state of the nerves succeeding another so rapidly, that the state of mental consciousness appropriate to each is not produced.'
Mr Mill gives various illustrations in support of this doctrine. He at the same time calls attention to a valuable lecture of Sir W. Hamilton's, the thirty-second lecture on Metaphysics; especially to the instructive citation from Cardaillac contained therein, noting the important fact, which descriptions of the Law of Association often keep out of sight—that the suggestive agency of Association is carried on, not by single antecedents raising up single consequents, but by a mass of antecedents raising up simultaneously a mass of consequents, among which attention is very unequally distributed.
We shall say little upon Mr Mill's remarks on Sir W. Hamilton's Theory of Causation—(chap. xvi.). This theory appears to Mr Mill absurd; while the theory of Mr Mill (continued from Hume, Brown, and James Mill) on the same subject, appears to Sir W. Hamilton insufficient and unsatisfactory—'professing to explain the phenomenon of causality, but, previously to explanation, evacuating the phenomenon of all that desiderates explanation'—(p. 295). For ourselves we embrace the theory of Mr Mill:[[13]] yet we are aware that the remark just cited from Sir W. Hamilton represents the dissatisfaction entertained towards it by many objectors. The unscientific and antiscientific yearnings, prevalent among mankind, lead them to put questions which no sound theory of Causation will answer; and they are ready to visit and trust any oracle which professes to deliver a confident affirmative solution of such questions. Among all the terms employed by metaphysicians, none is used in a greater variety of meanings than the term Cause.
In Mr Mill's next chapter (xvi.) he comments on Sir W. Hamilton's doctrine of Concepts or General Notions. There are portions of this chapter with which we agree less than with most other parts of the volume; especially with his marked hostility to the term Concept, and the reasons given for it, which reasons appear to us not very consistent with what he has himself said in the 'System of Logic,' Book IV. chap. ii. § 1—3. The term Concept has no necessary connection with the theory called Conceptualism. It is equally available to designate the idea called up by a general name, as understood either by Mr Bailey or by James Mill. We think it useful as an equivalent to the German word Begriff, which sense Sir W. Hamilton has in view when he introduces it, though he does not always adhere to his profession. And when Mr Mill says (p. 331)—
'I consider it nothing less than a misfortune, that the words Concept, General Notion, or any other phrase to express the supposed mental modification corresponding to a general name, should ever have been invented.'
we dissent from his opinion. To talk of 'the Concept of an individual,' however, as Mr Mansel does (pp. 338, 339), is improper and inconsistent with the purpose for which the name is given.