7. (1) Friction alters the temperature of the bodies rubbed together. (2) The sun is supposed to move through space. (3) A ray of light passing into or out of a denser medium is deflected. Point out the successive questions which would have to be decided in the investigation of the above phenomena. 8. Find some simple instances of the homogeneous and heterogeneous intermixture of effects, and of the methods of concomitant variations and residues. 9. Since 1842 there has been a great reform of the British tariff, and a great increase of British trade. Does this coincidence prove that the first circumstance is the cause of the second? 10. Supposing us to be unacquainted with the causes of the following phenomena, by what methods should we investigate each? (1) The connection between the barometer and the weather. (2) A person poisoned at a meal. (3) The connection between the hands of a clock. (4) The effect of the Gulf-stream upon the climate of Great Britain. LESSON XXX.-Empirical and Deductive Methods. 1. Define Empirical Law, and find a few additional instances of such laws. 2. What are the three steps of the Deductive Method? 3. Trace some of the successive steps in the progress of the theory of gravitation, showing that it was established by this method. LESSON XXXI.-Explanation, &c. 1. What do you mean by the explanation of a fact? 2. State the three ways in which a law of nature may be explained, and suggest some additional instances of each case. 3. Define tendency. Do all causes consist only of tendencies, or can you find examples to the contrary? 4. Give a definition of hypothesis. How may a valid be distinguished from an invalid hypothesis? 5. What place does hypothesis hold in the Deductive Method? 6. Explain the ambiguities of the words theory and fact. LESSON XXXII.—Classification. 1. Define classification, and give the derivation of the word. 2. What do you mean by important characters in classification? 3. State Dr Whewell's criterion of a good natural arrangement. 4. Distinguish between a natural and artificial system of classification. 5. What do you mean by a characteristic quality? Is it always an important quality? 6. Define abstraction, generalization, and colligation of facts. 7. What are the characters of a notion properly abstracted? LESSON XXXIII.-Requisites of a Philosophical Language. 1. What are the three purposes for which we use language? 2. What are the two chief requisites of a philosophical language? 3. By what considerations should we be guided in choosing between a new and old scientific term? 4. Distinguish a Descriptive Terminology and a Nomenclature; separate the following terms according as they belong to one or the other :Rose, Rosaceæ, Rose-like, Potassium, Alkaloid, Ruminant Animal, Ruminating, Ruby, Ruby-red. 5. What does Mr Mill mean by the expression Natural Kind? : INDEX, AND CONCISE VOCABULARY OF LOGICAL AND PHILOSOPHICAL TERMS. Abacus, the logical, 199 Abscissio Infiniti (the cutting off of the infinite or negative part), the process by which we determine the position of an object in a system of classes, by successive comparison and rejection of those classes to which it does not belong. Absolute terms, i.e. non-relative terms, 25 sometimes used as name of non-connotative terms, 41 Abstract terms, 20, 43 Abstraction, 285 Accent, fallacy of, 174 Accident, fallacy of, 176; the predicable, 103 Accidental definition is a definition which assigns the properties of a species, or the accidents of an individual; it is more commonly called a Description. Acquired perceptions, 236 Added determinants, inference by, 86 Adequate knowledge, 56 A dicto secundum quid, &c., Affirmative propositions, 63 Analogy, the cause of ambiguity, 35, 50; reasoning by, 226-8 Analytics, (тà "AvaλuTɩkà,) the title given in the second century to portions of the Organon, or Logical Treatises of Aristotle; they were distinguished as the Prior and Posterior Analytics. Analytic syllogism, a syllogism in which the conclusion is placed first, the premises following as the reasons. See Synthetic Syllogism; the distinction is unimportant. Antecedent, of a hypothetical proposition, 160; of an event, 240 Anticipation of nature, 229 Antinomy (avr, against; vóμos, law), the opposition of one law or rule to another. Kant. A posteriori knowledge, 208 Argument, (Latin, argus, from apyòs, clear, manifest,) the process of reasoning, the shewing or proving that which is doubtful by that which is known. See Inference. The middle term of a syllogism is sometimes called specially the argument. Argumentum a fortiori, an argument in which we prove that the case in question is more strong or probable than one already conceded to be sufficiently so. Argumentum ad hominem, 178 Argumentum ad judicium, an appeal to the common sense of mankind. Argumentum ad ignoranti- 179 Argumentum ad verecun- diam, an appeal to our respect for Aristotle's Dicta, 123 Association of ideas, (associo, to Attribute, (attribuo, to give or Attribute in grammar, 92 Axiom, defininition of, 125 Baconian method, 255; Philoso- Barbara, Celarent, &c., 145 Boole, George, his system of Logic, Canons of syllogism, 121-2; Hamil- ton's supreme Canon, 189 Ovoía, Substance; Ilogòv, Quan- Everything which can be affirmed Cause, meaning of, 239 Aristotle distinguished four kinds Chance, ignorance of the causes Characteristics, 285 Circulus in definiendo, 110, 114 Colligation of Facts, Dr Whewell's Collective terms, 19 Combined or complete method of |