SOPHISM, in logic, &c. an argument which carries much of the appearance of truth, and yet leads into error. There is some need of a particular description of these fallacious arguments, that we may with more ease and readiness detect and solve them. 1. The first sort of sophism is called" ignoratio elenchi ;" or a mistake of the question. 2. The next sophism is called" petitio principii," or a supposition of what is not granted. 3. That sort of fallacy, which is called a circle, is very near a-kin to the " petitio principii." 4.The next sort of sophism is called " non causa pro causa," or the assignation of a false cause. 5. The next is called " fascia accidentis," or a sophism, wherein we pro nounce concerning the nature and essen tial properties of any subject, according to something which is merely accidental to it. 6. The next sophism borders upon the former ; and that is, when we argue from that which is true, absolutely, sim ply, and abstracted from all circumstan ces; this is called, in the schools, a sophism " a dicto secundum quid ad dic tum simpliciter." This sort of sophism has also its reverse; as, when we argue from that which is true, simply and ab solutely, to prove the same thing true in all particular circumstances whatsoever. 7. The sophisms of composition and divi sion come next to be mentioned. The sophism of composition is, when we infer any thing concerning ideas in a com pound sense, which is only true in a di vided sense. The sophism of division is, when we infer the same thing concerning ideas in a divided sense, which is only true in a compounded one. This sort of
sophism is committed, when the word all is taken in a collective and distributive sense, without a due distinction. It is the same fallacy, when the universal word all, or no, refers to specks in one proposition, and to the individuals in another. 8. The last sort of sophisms arises from our abuse of the ambiguity of words, which is the largest and most extensive kind of fallacy ; and, indeed, several of the former fallacies might he reduced to this head. When the words or phrases are plainly equivocal, they are called sophisms of equivocation. This sophism, as well as the foregoing, and all of the like nature, are solved, by showing the different senses of the words, terms, or phra ses.
Bnt where such gross equivocations and ambiguities appear in arguments, there is little danger in imposing on our selves or others; the greatest danger, and what we arc perpetually exposed to in reasoning, is, where the two senses or significations of one term are near a-kin, and not plainly distinguished ; and yet are sufficiently different in their sense to lead us into great mistakes, it' we are not watchful. And, indeed, the greatest part of controversies, in the sacred or civil life, arise from the different senses that are put upon words, and the different ideas conveyed by them.