353
Sec.6. Difficulties of Definition 356
Proposals to substitute the Type (p. 356)
Sec.7. The Limits of Definition 357
Sec.8. The five Predicables 358
Porphyry's Tree (p. 361)
Sec.9. Realism and Nominalism 364
Sec.10. The Predicaments 366

CHAPTER XXIII

DEFINITION OF COMMON TERMS

Sec.1. The rigour of scientific method must be qualified 369
Sec.2. Still, Language comprises the Nomenclature of an imperfect
Classification, to which every Definition is relative; 370
Sec.3. and an imperfect Terminology 374
Sec.4. Maxims and precautions of Definition 375
Sec.5. Words of common language in scientific use 378
Sec.6. How Definitions affect the cogency of arguments 380

CHAPTER XXIV

FALLACIES

Sec.1. Fallacy defined and divided 385
Sec.2. Formal Fallacies of Deduction 385
Sec.3. Formal Fallacies of Induction 388
Sec.4. Material Fallacies classified 394
Sec.5. Fallacies of Observation 394
Sec.6. Begging the Question 396
Sec.7. Surreptitious Conclusion 398
Sec.8. Ambiguity 400
Sec.9. Fallacies, a natural rank growth of the Human mind, not
easy to classify, or exterminate 403

QUESTIONS 405

LOGIC

CHAPTER I

INTRODUCTORY

Sec. 1. Logic is the science that explains what conditions must be
fulfilled in order that a proposition may be proved, if it admits of
proof. Not, indeed, every such proposition; for as to those that declare
the equality or inequality of numbers or other magnitudes, to explain
the conditions of their proof belongs to Mathematics: they are said to
be _quantitative_. But as to all other propositions, called
_qualitative_, like most of those that we meet with in conversation, in
literature, in politics,