A System of Logic: Ratiocinative and Inductive, 7th Edition, Vol. I — John Stuart Mill — John Shaqi
A System of Logic: Ratiocinative and Inductive, 7th Edition, Vol. I
John Stuart Mill · en
[8] It is hardly necessary to say, that I am not contending for any such
absurdity as that we _actually_ "ought to have known" and considered the
case of every individual man, past, present, and future, before
affirming that all men are mortal: although this interpretation has
been, strangely enough, put upon the preceding observations. There is no
difference between me and Archbishop Whately, or any other defender of
the syllogism, on the practical part of the matter; I am only pointing
out an inconsistency in the logical theory of it, as conceived by almost
all writers. I do not say that a person who affirmed, before the Duke of
Wellington was born, that all men are mortal, _knew_ that the Duke of
Wellington was mortal; but I do say that he _asserted_ it; and I ask for
an explanation of the apparent logical fallacy, of adducing in proof of
the Duke of Wellington's mortality, a general statement which
presupposes it. Finding no sufficient resolution of this difficulty in
any of the writers on Logic, I have attempted to supply one.
[9] The language of ratiocination would, I think, be brought into closer
agreement with the real nature of the process, if the general
propositions employed in reasoning, instead of being in the form All men
are mortal, or Every man is mortal, were expressed in the form Any man
is mortal. This mode of expression, exhibiting as the type of all
reasoning from experience "The men A, B, C, &c. are so and so, therefore
_any_ man is so and so," would much better manifest the true idea--that
inductive reasoning is always, at bottom, inference from particulars to
particulars, and that the whole function of general propositions in
reasoning, is to vouch for the legitimacy of such inferences.
[10] Review of Quetelet on Probabilities, _Essays_, p. 367.
[11] _Philosophy of Discovery_, p. 289.
[12] _Theory of Reasoning_, ch. iv. to which I may refer for an able
statement and enforcement of the grounds of the doctrine.
[13] It is very probable that the doctrine is not new, and that it was,
as Sir John Herschel thinks, substantially anticipated by Berkeley. But
I certainly am not aware that it is (as has been affirmed by one of my
ablest and most candid critics) "among the standing marks of what is
called the empirical philosophy."
[14] _Logic_, book iv. ch. i. sect. 1.
[15] See the important chapter on Belief, in Professor Bain's great
treatise, _The Emotions and the Will_, pp. 581-4.