68. How do you distinguish between what Mill calls the Geometrical, Physical, and Historical Methods? 68A. The Comparative Method is appealed to where direct evidence is wanting. Explain this. 69. What is meant by a doctrine being unverifiable? If a conclusion reached by deduction does not agree with the facts, where must we look for error? 70. There are certain cases in which failure of verification is fatal to a theory, and other cases in which it is of comparatively little cogency. How would you distinguish between these classes of cases? [S] 71. Taking the "evolution," or any other proposed hypothesis, how should one proceed (a) to show whether it satisfies the conditions of a legitimate hypothesis sufficiently to entitle it to investigation, and (b) to test it with a view to its acceptance or rejection as a truth of science? [S] 72. What do you mean by saying that "a phenomenon has been satisfactorily explained"? 73. Explain and illustrate the Historical Method of Sociological inquiry. [S] 74. What is the relation of the theory of Probability to Logic? [S] 75. Explain and discuss the doctrine that Induction is based upon the Theory of Probability. [S] 75A. What are the logical grounds of the Law of Error? 76. Explain the nature and use of Classification, the means to, and tests of, its successful performance. [S] 77. What is Definition and what is its use? Mention various difficulties that occur in the process, and show how they are to be met. [S] 78. Propose rules for a good Division and a good Definition, and exemplify the breach of them. [S] 79. Examine the validity of the idea of Real Kinds. [O] 80. What kind of words are indefinable, and why? When do we define by negation and by example? [S] 81. Distinguish between the province and aims of classification and (logical) division. Illustrate. [S] 82. What is an _infima species_ or _species specialissima_? Compare the use of the terms _genus_ and _species_ in Logic with that which is common in speaking of animals or plants. [S] 83. How far does the formation of Definitions and Classifications constitute the end of Science? [S] 84. Examine the methodological relations between Definition, Classification and Nomenclature. [S] 85. Give instances of "Differentia," "Property," "Inseparable Accident"; and examine, with reference to your instances, how far it is possible to distinguish them. [S] V. MISCELLANEOUS. 86. "People can reason without the help of Logic." Why is this not a sufficient objection to the study? In your answer show distinctly why Logic should be studied. [S] 87. What is the meaning of the assertion that Logic is concerned with the form, and not with the matter, of thought? [S] 88. "Neither by deductive nor inductive reasoning can we add a tittle to our implicit knowledge." (Jevons.) Explain and criticise. [S] 89. What is the logical foundation of the indirect method or _reductio ad absurdum_? Is it applicable to non-mathematical subjects? [S]