“It is evident that Ignoratio Elenchi may be employed as well for the apparent refutation of your opponent’s proposition, as for the apparent establishment of your own; for it is substantially the same thing, to prove what was not denied or to disprove what was not asserted. The latter practice is not less common, and it is more offensive, because it frequently amounts to a personal affront, in attributing to a person opinions, etc., which he perhaps holds in abhorrence. Thus, when in a discussion one party vindicates, on the ground of general expediency, a particular instance of resistance to government in a case of intolerable oppression, the opponent may gravely maintain, ‘that we ought not to do evil that good may come;’ a proposition which of course had never been denied, the point in dispute being, ‘whether resistance in this particular case were doing evil or not.’ Or again, by way of disproving the assertion of the right of private judgment in religion, one may hear a grave argument to prove that ‘it is impossible every one can be right in his judgment.’ ”
The works of controversial writers are seldom free from this fallacy. The attempts, for instance, to disprove the population doctrines of Malthus, have been mostly cases of ignoratio elenchi. Malthus has been supposed to be refuted if it could be shown that in some countries or ages population has been nearly stationary; as if he had asserted that population always increases in a given ratio, or had not expressly declared that it increases only in so far as it is not restrained by prudence, or kept down by poverty and disease. Or, perhaps, a collection of facts is produced to prove that in some one country the people are better off with a dense population than they are in another country with a thin one; or that the people have become more numerous and better off at the same time. As if the assertion were that a dense population could not possibly be well off; as if it were not part of the very doctrine, and essential to it, that where there is a more abundant production there may be a greater population without any increase of poverty, or even with a diminution of it.
The favorite argument against Berkeley’s theory of the non-existence of matter, and the most popularly effective, next to a “grin”[267]—an argument, moreover, which is not confined to “coxcombs,” nor to men like Samuel Johnson, whose greatly overrated ability certainly did not lie in the direction of metaphysical speculation, but is the stock argument of the Scotch school of metaphysicians—is a palpable Ignoratio Elenchi. The argument is perhaps as frequently expressed by gesture as by words, and one of its commonest forms consists in knocking a stick against the ground. This short and easy confutation overlooks the fact, that in denying matter, Berkeley did not deny any thing to which our senses bear witness, and therefore can not be answered by any appeal to them. His skepticism related to the supposed substratum, or hidden cause of the appearances perceived by our senses; the evidence of which, whatever may be thought of its conclusiveness, is certainly not the evidence of sense. And it will always remain a signal proof of the want of metaphysical profundity of Reid, Stewart, and, [pg 578] I am sorry to add, of Brown, that they should have persisted in asserting that Berkeley, if he believed his own doctrine, was bound to walk into the kennel, or run his head against a post. As if persons who do not recognize an occult cause of their sensations could not possibly believe that a fixed order subsists among the sensations themselves. Such a want of comprehension of the distinction between a thing and its sensible manifestation, or, in metaphysical language, between the noumenon and the phenomenon, would be impossible to even the dullest disciple of Kant or Coleridge.
It would be easy to add a greater number of examples of this fallacy, as well as of the others which I have attempted to characterize. But a more copious exemplification does not seem to be necessary; and the intelligent reader will have little difficulty in adding to the catalogue from his own reading and experience. We shall, therefore, here close our exposition of the general principles of logic, and proceed to the supplementary inquiry which is necessary to complete our design.
Book VI.
On The Logic Of The Moral Sciences.
“Si l’homme peut prédire, avec une assurance presque entière, les phénomènes dont il connaît les lois; si lors même qu’elles lui sont inconnues, il peut, d’après l’expérience, prévoir avec une grande probabilité les événements de l’avenir; pourquoi regarderait-on comme une entreprise chimérique, celle de tracer avec quelque vraisemblance le tableau des destinées futures de l’espèce humaine, d’après les résultats de son histoire? Le seul fondement de croyance dans les sciences naturelles, est cette idée, que les lois générales, connues ou ignorées, qui règlent les phénomènes de l’univers, sont nécessaires et constantes; et par quelle raison ce principe serait-il moins vrai pour le développement des facultés intellectuelles et morales de l’homme, que pour les autres opérations de la nature? Enfin, puisque des opinions formées d’après l’expérience ... sont la seule règle de la conduite des hommes les plus sages, pourquoi interdirait-on au philosophe d’appuyer ses conjectures sur cette même base, pourvu qu’il ne leur attribue pas une certitude supérieure à celle qui peut naître du nombre, de la constance, de l’exactitude des observations?”—Condorcet, Esquisse d’un Tableau Historique des Progrès de l’Esprit Humain.