An argument which can be answered by reductio ad ab surdum is said to prove too much,- that is, too much for its force as an argument; since, if the conclusion is true, a general proposition which lies behind it and includes it is also true. To show this general proposition in its absurdity is to overthrow the conclusion. The argument carries in itself the means of its own destruction. For example: (1) Skill in public speaking is liable to great abuse; it should, therefore, not be cultivated. (2) Skill in public speaking is liable to great abuse; but so are the best things in the world, - as health, wealth, power, military skill; the best things in the world should, therefore, not be cultivated. In this example, the indirect argument under (2) overthrows the direct argument under (1) by bringing into view the general proposition omitted from (1) but implied in it, — namely, that nothing which is liable to great abuse should be cultivated. absurdity of this general proposition is made apparent by the specific instances cited. The The argument that games of football should be given up because players sometimes sustain severe injuries may be disposed of in a similar way; for horseback-riders and boating-men are not exempt from danger. In Plato's dialogues, Socrates often applies reductio ad absurdum to the argument of an opponent. Thus, in "The Republic," Thrasymachus lays down the principle that justice is the interest of the stronger. This principle he explains by saying that the power in each State is vested in the rulers, and that, therefore, justice demands that which is for the interest of the rulers. Whereupon Socrates makes him admit that it is just for subjects to obey their rulers, and also that rulers, not being infallible, may unintentionally command that which is to their own injury. "Then justice, according to your argument," concludes Socrates, "is not only the interest of the stronger but the reverse.' 1 See Aristotle: Rhetoric, book i. chap. i. 2 See Jowett's Plato, vol. ii. pp. 159–161. n Another example of reductio ad absurdum is furnished by the reply to the arguments which attempt to prove by means of an alleged cipher that Bacon wrote the plays attributed to Shakspere. All the arguments adduced in favor of this proposition may, as its opponents contend, be used to prove that anybody wrote anything. In a direct argument, a reasoner openly seeks to establish, or to refute, a proposition. In an indirect argument, he often masks his purpose in order the more surely to prove the falsity of his opponent's arguments: he pretends to agree with them; he maintains with mock seriousness irony- the opposite of that which he himself believes. Well-known instances of ironical argument are Burke's "Vindication of Natural Society," in which Bolingbroke's arguments against religious institutions are applied to civil society; Defoe's "Shortest Way with Dissenters," in which the author personates a "High-flier" (that is, a Tory with extreme High-church views) in order to prove that the doctrines of such a man would justify the burning of dissenters; Swift's "Argument against the Abolishment of Christianity," and his "Modest Proposal" for relieving Ireland from famine by having the children cooked and eaten; Whately's "Historic Doubts," in which Hume's arguments against Christianity are used to prove that Napoleon Bonaparte never lived. Before beginning to argue, a reasoner not only should have clearly in mind the proposition in dispute, but should know on which side rests the burden Burden of of proof. The general rule in this matter presumption. is embodied in the legal maxim that "he who affirms must prove." proof and "The burden of proof as to any particular fact lies on that per son who wishes the Court to believe in its existence, unless it is provided by any law that the burden of proving that fact shall lie on any particular person. ... "A prosecutes B for theft, and wishes the Court to believe that B admitted the theft to C. A must prove the admission. "B wishes the Court to believe that, at the time in question, he was elsewhere. He must prove it." 1 The burden of proof rests upon those who advocate any change in the established order of things, - upon those, for instance, who maintain that the Anglican Church should be disestablished, that the House of Lords or the Senate of the United States should be abolished, that the right of suffrage should be extended to a class of persons who do not now enjoy it, that free-trade should be substituted (in the United States) for protection, cremation for burial, "faith cure" for medical treatment. A reasoner upon whom the burden of proof does not rest has, usually, the presumption 2 in his favor; that is to say, the proposition he maintains is assumed to be true in the absence of proof to the contrary. He upon whom the burden of proof rests, and against whom the presumption lies, must overcome the presumption against him by throwing enough evidence into the opposite scale to raise a counter-presumption. The amount of evidence required will vary according as the presumption to be rebutted is weak or strong. The presumption in favor of an established institution may be rebutted by evidence tending to show that the institution in question is an obstacle to the successful working of some other established institution the superior value of which is admitted. There is a presumption in 1 Sir James Fitzjames Stephen: A Digest of the Law of Evidence, chap. xiii. art. xcvi. 2 From prae, before, and sumere, to take. favor of a system of laws under which a country has flourished; but if another country, similarly situated, has been still more prosperous under a different system of laws, there is a counter-presumption that the prosperity of the first country is due to other causes than her laws. A counter-presumption which rebuts the original presumption may in its turn be rebutted by additional evidence; and thus, in the course of a long discussion, each side may several times enjoy the advantage of the presumption. A reasoner should always avail himself of a presumption in his favor, if one exists, and should never unnecessarily assume the burden of proof. In criminal cases, the question upon whom rests the burden of proof may be a question of life or death.1 "A moderate portion of common-sense," says Whately, "will enable any one to perceive, and to show, on which side the presumption lies, when once his attention is called to this question; though, for want of attention, it is often overlooked: and on the determination of this question the whole character of a discussion will often very much depend. A body of troops may be perfectly adequate to the defence of a fortress against any attack that may be made on it; and yet, if, ignorant of the advantage they possess, they sally forth into the open field to encounter the enemy, they may suffer a repulse. At any rate, even if strong enough to act on the offensive, they ought still to keep possession of their fortress. In like manner, if you have the 'presumption' on your side, and can but refute all the arguments brought against you, you have, for the present at least, gained a victory: but if you abandon this position, by suffering this 'presumption' to be forgotten, which is in fact leaving out one of, perhaps, your strongest arguments, you may appear to be making a feeble attack, instead of a triumphant defence.” 2 1 See York's Case, 9 Metcalf's (Massachusetts) Rep. 93. SECTION 1. EVIDENCE. Evidence, the material of proof, is furnished directly by our own senses or consciousness, or indirectly (as in testimony, tradition, or documents) through the senses or the consciousness of others. and matters of opinion. If the evidence of our senses were confined to mere matters of fact, it would be more trustworthy than it is; Matters of fact but in almost all that we see, or rather say that we see, facts are mingled with inferences from facts. We speak of seeing an orange, for example; but what we do see is an object of a certain shape and color which experience justifies us in calling an orange. In this case, fact and inference seem to be merged in one. That they are not one is proved by common experience: we often imagine that we see what we do not see. A yellow ball, for example, may be mistaken for an orange, a white cloud for a snow-capped mountain, one person for another, one sound for another. In such cases, the mistake is not in fact but in inference from fact: what seemed a matter of fact turns out to be a matter of opinion. The difference between so-called matters of fact and so-called matters of opinion is, then, a difference beween matters in which the element of observed fact preponderates and those in which the element of inference from observed fact preponderates. Sometimes it is hard to tell whether what we are speaking of is matter of fact or matter of opinion, since opinion enters into almost all statements with regard to matters of fact, and since, the instant a reasonable doubt is raised concern |