A System of Logic: Ratiocinative and Inductive, 7th Edition, Vol. II
John Stuart Mill · en
country under a tyranny is distressed,' which, however true, proves
nothing, the middle term being undistributed." The former would be
ranked, in our distribution, among fallacies of generalization, the
latter among those of ratiocination. "Which are we to suppose the
speaker meant us to understand? Surely" (if he understood himself) "just
whichever each of his hearers might happen to prefer: some might assent
to the false premise; others allow the unsound syllogism."
Almost all fallacies, therefore, might in strictness be brought under
our fifth class, Fallacies of Confusion. A fallacy can seldom be
absolutely referred to any of the other classes; we can only say, that
if all the links were filled up which should be capable of being
supplied in a valid argument, it would either stand thus (forming a
fallacy of one class), or thus (a fallacy of another); or at furthest we
may say, that the conclusion is most _likely_ to have originated in a
fallacy of such and such a class. Thus in the illustration just quoted,
the error committed may be traced with most probability to a fallacy of
generalization; that of mistaking an uncertain mark, or piece of
evidence, for a certain one; concluding from an effect to some one of
its possible causes, when there are others which would have been equally
capable of producing it.
Yet, though the five classes run into each other, and a particular error
often seems to be arbitrarily assigned to one of them rather than to any
of the rest, there is considerable use in so distinguishing them. We
shall find it convenient to set apart, as Fallacies of Confusion, those
of which confusion is the most obvious characteristic; in which no other
cause can be assigned for the mistake committed, than neglect or
inability to state the question properly, and to apprehend the evidence
with definiteness and precision. In the remaining four classes I shall
place not only the cases in which the evidence is clearly seen to be
what it is, and yet a wrong conclusion drawn from it, but also those in
which, although there be confusion, the confusion is not the sole cause
of the error, but there is some shadow of a ground for it in the nature
of the evidence itself. And in distributing these cases of partial
confusion among the four classes, I shall, when there can be any
hesitation as to the precise seat of the fallacy, suppose it to be in
that part of the process in which, from the nature of the case, and the
tendencies of the human mind, an error would in the particular
circumstances be the most probable.
After these observations we shall proceed, without further preamble, to
consider the five classes in their order.
CHAPTER III.
FALLACIES OF SIMPLE INSPECTION; OR _À PRIORI_ FALLACIES.