(55) All scientific treatises that are clear and true deserve attention. Few scientific treatises are clear and true. .'. Few scientific treatises deserve attention. (56) The Conservative Government is an expensive one; for, on their going out of Office, there was a deficit. (57) A man is forbidden to marry his brother's wife, or, in other words, a woman is forbidden to marry her husband's brother, that is, a woman is directly forbidden to marry two brothers. Therefore a man may not marry two sisters, so that a man may not marry his wife's sister. INDEX. The references refer to the sections. Abstraction, 97. Acategorematic words, 71. Accent, Fallacy of, 855. Accident, 318. Accident, Fallacy of, 860. A dicto secundum quid, Fallacy of, 861. Amphiboly, Fallacy of, 848. Antecedent of a complex proposition, 212. of an inference, 428. A posteriori Truth, 232. A priori Truth, 231. 'A' Propositions, 260. conversion of, 489. Arguing in a circle, 882. Argumentum ad hominem, etc., 867. Art, 20. Attribute, 81 sqq. Essential and non-essential, 320. Attributives, 88 sqq. Basis of Division, 391. Categorematic words, 71. Circulus in definiendo, 382. Common Terms, 105. how formed, 99. nature of, 48. Complex Proposition, 209. conversion of, 709. conversion by contraposition of, 728. conversion by negation of, 721. divided into conjunctive and disjunctive, 214. permutation of, 718. Complex Syllogism, 731. mixed form of, 778. Composition, Fallacy of, 849. Concept, 36, 40 sqq. Conception, 33. Conceptualists, 51. Conclusion, 540. predicate of, 542. subject of, 542. Conjunctive Syllogisms, 733. canon of, 742. reduction of partly, 744. partly conjunctive syllogisms as an immediate inference, 753. Connotation of Terms, 148. Consequent of a complex proposition, 213. of an inference, 428. Consequent, Fallacy of, 873. Contingent, 17. Contradiction, Law of, 25 sqq. Contradictory Propositions, 458. Terms, 129. Contrary Propositions, 458. Terms, 130. Converse, 480. Conversion, 479. of complex propositions, 709. by contraposition, 516. illative, 481. by negation, 504. per accidens, 487. simple, 486. rules of, 482. Convertend, 480. Copula, 58, 64, 186 sqq. modality of, 196. Correlatives, 142. Deduction and Induction, difference of, 431 sqq. Deductive Inference, 442. Deductive Logic, definition of, 4. Definition of Terms, 347 sqq. of Aristotle ([Greek: òrismós]), 336. final, 374. nominal, 375. provisional, 374. real, 375. rules of, 378. Denotation of Terms, 152. Description, 360. Designations, 112. Determination, 167. Dictum de omni et nullo, 569. de diverso, 641. de exemplo et excepto, 642. Difference, 318, 358. generic, 410. specific, 409. Dilemma, 732, 779. rebutted, 792. reduction of, 796. regarded as an immediate inference, 798.