299. Care to be used in correctly stating the subject of discussion. 300. Consider the kind of evidence applicable to the subject 302. Fallacia equivocationis, or the use of equivocal terms and phrases 378 303. On the sophism of estimating actions and character from the cir- 306 Imagination an intellectual process, closely related to reasoning 383 307. Definition of the power of imagination 309. Process of the mind in the creations of the imagination 309. Further remarks on the same subject 310. Illustration from the writings of Dr. Reid 311. Grounds of the preference of one conception to another 312. Illustration of the subject from Milton. 313. The creations of the imagination not entirely voluntary 314. Illustration of the statements of the preceding section 316. Works of imagination give different degrees of pleasure 317 Importance of the imagination in connexion with reasoning CHAP. XV.-COMPLEX IDEAS OF INTERNAL ORIGIN. 321. Of complex ideas of external origin 322. Nature of complex ideas of internal origin 323. Of complex notions formed by the repetition of the same thing 324. Of the help afforded by names in the combination of numbers 325. Instances of complex notions made up of different simple ideas 328. Disordered intellectual action connected with the body 329. The mind constituted on the principle of a connexion with the body 412 330. Illustration of the subject from the effects of old age 331 The connexion of the bodily system with the mental shown from the effects resulting from diseases 332. Shown also from the effects of stimulating drugs and gases 333. Influence on the body of excited imagination and passion 334. This doctrine of use in explaining mental phenomena CHAP. II.-EXCITED CONCEPTIONS OR APPARITIONS. 335 Of excited conceptions and of apparitions in general 338. First cause of permanently vivid conceptions or apparitions. Morbid sensibility of the retina of the eye 339. Second cause of permanently excited conceptions or apparitions. 340. Methods of relief adopted in this case. 341. Third cause of excited conceptions. Attacks of fever 342. Fourth cause of apparitions and other excited conceptions. In- 422 424 426 427 428 CHAP. III.-PARTIAL INSANITY. 345. Meaning of the term and kinds of insanity 346. Of disordered or alienated sensations 347. Of disordered or alienated external perception 348. Disordered state or insanity of original suggestion 349. Unsoundness or insanity of consciousness 350. Insanity of the judgment or relative suggestion 351. Disordered or alienated association. Light-headedness 352. Illustrations of this mental disorder 353. Of partial insanity or alienation of the memory 354. Of the power of reasoning in the partially insane 355. Instance of the above form of disordered reasoning 356. Of readiness of reasoning in the partially insane 357. Partial mental alienation by means of the imagination 358. Insanity or alienation of the power of belief CHAP. IV. TOTAL INSANITY OR DELIRIUM. 359. Idea of total insanity or delirium 360. Of perception in cases of total or delirious insanity 363. Of the memory in connexion with delirious insanity 364. Of the power of reasoning in total or delirious insanity 365. Of the form of insanity called furor or madness 366. Of the causes of the different kinds of insanity 367. Of moral accountability in mental alienation INTRODUCTION. CHAPTER I. PRIMARY TRUTHS. 1. Importance of preliminary statements in Mental Philosophy. It is often highly important, in the investigation of a department of science, to state, at the commencement of such investigation, what things are to be considered as preliminary and taken for granted, and what are not. If this precaution had always been observed, which, where there is any room for mistake or misapprehension, seems so reasonable, many useless disputes would have been avoided, and the paths to knowledge, too often unnecessarily perplexed and prolonged, would have been rendered more direct and easy. It is impossible to proceed with inquiries in the science of MENTAL PHILOSOPHY, as it will be found to be in almost every other, without a proper understanding of those fundamental truths which are necessarily involved in what follows. And it will, accordingly, be the object of this chapter to endeavour to ascertain some of them. § 2. Nature of such preliminary statements. Those preliminary principles which may be found necessary to be admitted as the antecedents and conditions of all subsequent inquiries, will be called, for the sake of distinction and convenience, PRIMARY TRUTHS.-But what are these? Or how do we know them? According to the view of this subject taken by Buffier, who has expressly written upon it, and whose views are approved and adopted by Mr. Stewart, they are such, and such only, as can neither be proved nor refuted by other propositions of greater perspicuity. And this seems to be not only a succinct, but a satisfactory account of them, since, if there were other propositions into which they could be resolved, and by means of which they could be made clearer, then they could no longer be regarded as Primary, but those other clearer propositions would have that character. But it may be asked again, Are there any propositions of this kind? Are there any so clear, that the great instrument of human reasoning cannot render them more perspicuous? Can there not be a complete action of the human mind in all its parts without the laying down of any antecedent truths whatever, as auxiliaries in its efforts after knowledge ?-The answer to such questions, however formidable they may at first appear, is by no means difficult. In the first place, every man, who investigates at all, often experiences doubts in his inquiries. He accordingly endeavours to render such doubtful views clearer by argument. He goes on from step to step, from one proposition to another; but, unless he at last finds some truth utterly too clear to be rendered more so by reasoning, he must evidently proceed, adding deduction to deduction without end. His resting-place, accordingly, is in those truths which are elementary, and which illuminate the understanding by their own light, and not by a light let in from any other source.-Again, the nature of reasoning itself leads us to the same view. A process of reasoning is essentially the successive perception of relations; but there can be no feeling or perception of relation where there is but one object of contemplation. Something, therefore, must, from the nature of the case, be assumed as the antecedent, the basis, or necessary condition of every such process. § 3. Of the name or designation given them. We propose to call those propositions, which are so elementary as to be susceptible neither of proof nor of refutation from other propositions of greater clearness, PRIMARY TRUTHS. Such propositions are termed, in the first place, TRUTHS, since they are forced upon us, as it were, by our very constitution. They exist as surely as the mind exists, where they have their birthplace; they |