For example, your opponent states that in the original formation of a mountain-range the granite and other elements in its composition were, by reason of their high temperature, in a fluid or molten state; that the temperature must have amounted to some 480° Fahrenheit; and that when the mass took shape it was covered by the sea. You reply, by an argument _ad auditores_, that at that temperature--nay, indeed, long before it had been reached, namely, at 212° Fahrenheit--the sea would have been boiled away, and spread through the air in the form of steam. At this the audience laughs. To refute the objection, your opponent would have to show that the boiling-point depends not only on the degree of warmth, but also on the atmospheric pressure; and that as soon as about half the sea-water had gone off in the shape of steam, this pressure would be so greatly increased that the rest of it would fail to boil even at a temperature of 480°. He is debarred from giving this explanation, as it would require a treatise to demonstrate the matter to those who had no acquaintance with physics. XXIX.[1] [Footnote 1: See § xviii.] If you find that you are being worsted, you can make a _diversion_--that is, you can suddenly begin to talk of something else, as though it had a bearing on the matter in dispute, and afforded an argument against your opponent. This may be done without presumption if the diversion has, in fact, some general bearing on the matter; but it is a piece of impudence if it has nothing to do with the case, and is only brought in by way of attacking your opponent. For example, I praised the system prevailing in China, where there is no such thing as hereditary nobility, and offices are bestowed only on those who succeed in competitive examinations. My opponent maintained that learning, as little as the privilege of birth (of which he had a high opinion) fits a man for office. We argued, and he got the worst of it. Then he made a diversion, and declared that in China all ranks were punished with the bastinado, which he connected with the immoderate indulgence in tea, and proceeded to make both of them a subject of reproach to the Chinese. To follow him into all this would have been to allow oneself to be drawn into a surrender of the victory which had already been won. The diversion is mere impudence if it completely abandons the point in dispute, and raises, for instance, some such objection as "Yes, and you also said just now," and so on. For then the argument becomes to some extent personal; of the kind which will be treated of in the last section. Strictly speaking, it is half-way between the _argumentum ad personam_, which will there be discussed, and the _argumentum ad hominem_.