A System of Logic, Ratiocinative and Inductive — John Stuart Mill — John Shaqi
A System of Logic, Ratiocinative and Inductive
John Stuart Mill · en
Archbishop Whately has contended that syllogizing, or reasoning from
generals to particulars, is not, agreeably to the vulgar idea, a peculiar
_mode_ of reasoning, but the philosophical analysis of _the_ mode in which
all men reason, and must do so if they reason at all. With the deference
due to so high an authority, I can not help thinking that the vulgar
notion is, in this case, the more correct. If, from our experience of
John, Thomas, etc., who once were living, but are now dead, we are
entitled to conclude that all human beings are mortal, we might surely
without any logical inconsequence have concluded at once from those
instances, that the Duke of Wellington is mortal. The mortality of John,
Thomas, and others is, after all, the whole evidence we have for the
mortality of the Duke of Wellington. Not one iota is added to the proof by
interpolating a general proposition. Since the individual cases are all
the evidence we can possess, evidence which no logical form into which we
choose to throw it can make greater than it is; and since that evidence is
either sufficient in itself, or, if insufficient for the one purpose, can
not be sufficient for the other; I am unable to see why we should be
forbidden to take the shortest cut from these sufficient premises to the
conclusion, and constrained to travel the “high priori road,” by the
arbitrary fiat of logicians. I can not perceive why it should be
impossible to journey from one place to another unless we “march up a
hill, and then march down again.” It may be the safest road, and there may
be a resting-place at the top of the hill, affording a commanding view of
the surrounding country; but for the mere purpose of arriving at our
journey’s end, our taking that road is perfectly optional; it is a
question of time, trouble, and danger.