CONTENTS. 



CHAPTER VII. 

 Of Classification, as subsidiary to Induction. 



() 1. Classification, as here treated of, 

 wherein diflerent from the classi- 

 fication implied in naming . . 432 



2. Theory of natural groups . . 433 



3. Are natural groups given by type, or 



by definition ? . . . . 436 



4. Kinds are natural groups . . 438 



5. How the names of Kinds should be 



constructed 441 



CHAPTER VIII. 

 Of Classification by Series. 



i) 1. Natural groups should be arranged 



in a natural series .... 443 



2. The arrangement should follow the 



degrees of the main phenomenon . 4-14 



3. — which implies the assumption of 



a type-species .... 445 



4. How the divisions of the series 



should be determined . . . 446 



5. Zoology aflfords the completest type 



of scientific classification . . 447 



BOOK V. 



ON FALLACIES. 



CHAPTER I. 

 Of Fallacies in general. 



() 1. Theory of fallacies a necessary part 



of logic 448 



2. Casual mistakes are not fallacies . 449 



3. The moral sources of erroneous 



opinion, how related to the intel- 

 lectual 450 



CHAPTER II. 



Classification of Fallacies. 



i) 1. On what criteria a classification of 



fallacies should be grounded . 451 



2. The five classes of fallacies . . 452 



3. The reference of a fallacy to one or 



other class is sometimes arbitrary 451 



CHAPTER III. 



Fallacies of Simple Inspection, or a priori 



Fallacies. 



§ 1. Character of this class of fallacies . 456 



2. Natural prejudice of mistaking sub- 



jective laws for objective, exempli- 

 fied in popular superstitioi^s . . 457 



3. Natural prejudices, that things 



which we thmk of together must 

 exist together, and that what is 

 inconceivable must be false . . 459 



4. Natural prejudice of ascribing ob- 



jective existence to abstractions . 463 



5. Fallacy of the Sufficient Reason . 464 



6. Natural prejudice, that the differ- 



ences in nature correspond to the 

 distinctions iii language . . 466 



7. Prejudice, that a phenomenon can- 



not have more than one cause . 468 



8. Prejudice, that the conditions of a 



phenomenon must resemble the 

 phenomenon 470 



CHAPTER IV. ^'^'' 



Fallacies of Observation. 

 ^ I. Non-observation, and Mal-observa- 



tion 475 



2. Non-observation of instances, and 



non-observation of circumstances, ib 



3. Examples of the former . . . 476 



4. — and of the latter . . . .479 



5. Mal-observation characterized and 



exemplified 482 



CHAPTER V. 



Fallacies of Generalization. 

 ij 1. Character of the class . . .485 



2. Certain kinds of generalization must 



always be groundless . . . ib. 



3. Attempts to resolve radically differ- 



ent phenomena into the same . 486 



4. Fallacy of mistaking empirical for 



causal laws 497 



5. Post hoc, ergo propter hoc ; and the 



deductive fallacy corresponding 

 to it 490 



6. Fallacy of False Analogies . . 491 



7. Function of metaphors in reasoning 495 



8. How fallacies of generalization grow 



out of bad classification . . 497 



CHAPTER VI. 



Fallacies of Ratiocination. 

 ^ 1. Introductory remarks . . .498 



2. Fallacies in the conversion and aequi- 



pollency of propositions . . ib. 



3. Fallacies in the syllogistic process . 499 



4. Fallacy of changing the premisses . ib. 



CHAPTER VII. 



Fallacies of Confusion. 

 ^ 1. Fallacy of Ambiguous Terms . . 502 



2. Fallacy of Petitio Principii . . 510 



3. Fallacy of Ignoratio Elenchi . .515 



BOOK VI. 



ON THE LOGIC OF THE MORAL SCIENCES. 



CHAPTER I. 



Introductory Remarks. 

 % 1. The backward state of the Moral 

 Sciences can only be remedied by 

 applying to them the methods of 

 Physical Science, duly extended 

 and generalized .... 519 

 2. How far this cati be attempted in 

 the present work . • . .520 



CHAPTER U. 



Of Liberty and Necessity. 

 ^ 1. Are human actions subject to the 



law of causality ? . . . . 521 



2. The doctrine commonly called Phil- 



osophical Necessity, in what sense 

 true 522 



3. Inappropriatcness and pernicious 



effect of the term Necessity . . 523 



4. A motive not always the anticipa- 



tion of a pleasure or a pain . . 526 



