This is the _argumentum ad verecundiam_. It consists in making an appeal to authority rather than reason, and in using such an authority as may suit the degree of knowledge possessed by your opponent.
Every man prefers belief to the exercise of judgment, says Seneca; and it is therefore an easy matter if you have an authority on your side which your opponent respects. The more limited his capacity and knowledge, the greater is the number of the authorities who weigh with him. But if his capacity and knowledge are of a high order, there are very few; indeed, hardly any at all. He may, perhaps, admit the authority of professional men versed in a science or an art or a handicraft of which he knows little or nothing; but even so he will regard it with suspicion. Contrarily, ordinary folk have a deep respect for professional men of every kind. They are unaware that a man who makes a profession of a thing loves it not for the thing itself, but for the money he makes by it; or that it is rare for a man who teaches to know his subject thoroughly; for if he studies it as he ought, he has in most cases no time left in which to teach it.
But there are very many authorities who find respect with the mob, and if you have none that is quite suitable, you can take one that appears to be so; you may quote what some said in another sense or in other circumstances. Authorities which your opponent fails to understand are those of which he generally thinks the most. The unlearned entertain a peculiar respect for a Greek or a Latin flourish. You may also, should it be necessary, not only twist your authorities, but actually falsify them, or quote something which you have invented entirely yourself. As a rule, your opponent has no books at hand, and could not use them if he had. The finest illustration of this is furnished by the French _curé_, who, to avoid being compelled, like other citizens, to pave the street in front of his house, quoted a saying which he described as biblical: _paveant illi, ego non pavebo_. That was quite enough for the municipal officers. A universal prejudice may also be used as an authority; for most people think with Aristotle that that may be said to exist which many believe. There is no opinion, however absurd, which men will not readily embrace as soon as they can be brought to the conviction that it is generally adopted. Example affects their thought just as it affects their action. They are like sheep following the bell-wether just as he leads them. They would sooner die than think. It is very curious that the universality of an opinion should have so much weight with people, as their own experience might tell them that its acceptance is an entirely thoughtless and merely imitative process. But it tells them nothing of the kind, because they possess no self-knowledge whatever. It is only the elect Who Say with Plato: [Greek: tois pollois polla dokei] which means that the public has a good many bees in its bonnet, and that it would be a long business to get at them.