The conclusion is irresistible if we admit the Major, because the Major covertly assumes the point to be proved. In truth, _if_ a body moves, it moves neither where it is nor where it is not, but from where it is to where it is not. Motion consists in change of place: the Major assumes that the place is unchanged, that is, that there is no motion. [Footnote 1: For the history of Hypothetical Syllogism see Mansel's _Aldrich_, Appendix I.] [Footnote 2: It may be argued that the change is not merely grammatical, and that the implication of a general proposition in a hypothetical and _vice versa_ is a strictly logical concern. At any rate such an implication exists, whether it is the function of the Grammarian or the Logician to expound it.] [Footnote 3: Some logicians prefer the form Either A is, or B is. But the two alternatives are propositions, and if "A is" represents a proposition, the "is" is not the Syllogistic copula. If this is understood it does not matter: the analysis of the alternative propositions is unessential.] CHAPTER VIII. FALLACIES IN DEDUCTIVE ARGUMENT.--PETITIO PRINCIPII AND IGNORATIO ELENCHI. The traditional treatment of Fallacies in Logic follows Aristotle's special treatise [Greek: Peri sophistikon elenchon]--Concerning Sophistical Refutations--Pretended Disproofs--Argumentative Tricks. Regarding Logic as in the main a protection against Fallacies, I have been going on the plan of taking each fallacy in connexion with its special safeguard, and in accordance with that plan propose to deal here with the two great types of fallacy in deductive argument. Both of them were recognised and named by Aristotle: but before explaining them it is worth while to indicate Aristotle's plan as a whole. Some of his Argumentative Tricks were really peculiar to Yes-and-No Dialectic in its most sportive forms: but his leading types, both Inductive and Deductive, are permanent, and his plan as a whole has historical interest. Young readers would miss them from Logic: they appeal to the average argumentative boy. He divides Fallacies broadly into Verbal Fallacies ([Greek: para ten lexin], _in dictione_), and Non-Verbal Fallacies ([Greek: exo tes lexeos], _extra dictionem_). The first class are mere Verbal Quibbles, and hardly deserve serious treatment, still less minute subdivision. The world was young when time was spent upon them. Aristotle names six varieties, but they all turn on ambiguity of word or structure, and some of them, being dependent on Greek syntax, cannot easily be paralleled in another tongue. (1) Ambiguity of word ([Greek: homonymia]). As if one were to argue: "All cold can be expelled by heat: John's illness is a cold: therefore it can be expelled by heat". Or: "Some afflictions are cheering, for afflictions are sometimes light, and light is always cheering". The serious confusion of ambiguous words is met by Definition, as explained at length in pt. ii. c i.