Old and new logic contrasted: being an attempt to elucidate, for
ordinary comprehension, how Lord Bacon delivered the human mind from
its 2,000 years' enslavement under Aristotle. By Justin Brenan.[706]
London, 1839, 12mo.
Logic, though the other exact science, has not had the sort of assailants
who have clustered about mathematics. There is a sect which disputes the
utility of logic, but there are no special points, like the quadrature of
the circle, which {331} excite dispute among those who admit other things.
The old story about Aristotle having one logic to trammel us, and Bacon
another to set us free,--always laughed at by those who really knew either
Aristotle or Bacon,--now begins to be understood by a large section of the
educated world. The author of this tract connects the old logic with the
indecencies of the classical writers, and the new with moral purity: he
appeals to women, who, "when they see plainly the demoralizing tendency of
syllogistic logic, they will no doubt exert their powerful influence
against it, and support the Baconian method." This is the only work against
logic which I can introduce, but it is a rare one, I mean in contents. I
quote the author's idea of a syllogism:
"The basis of this system is the syllogism. This is a form of couching the
substance of your argument or investigation into one short line or
sentence--then corroborating or supporting it in another, and drawing your
conclusion or proof in a third."
On this definition he gives an example, as follows: "Every sin deserves
death," the substance of the "argument or investigation." Then comes,
"Every unlawful wish is a sin," which "corroborates or supports" the
preceding: and, lastly, "therefore every unlawful wish deserves death,"
which is the "conclusion or proof." We learn, also, that "sometimes the
first is called the premises (_sic_), and sometimes the first premiss"; as
also that "the first is sometimes called the proposition, or subject, or
affirmative, and the next the predicate, and sometimes the middle term." To
which is added, with a mark of exclamation at the end, "but in analyzing
the syllogism, there is a middle term, and a predicate too, in each of the
lines!" It is clear that Aristotle never enslaved this mind.
I have said that logic has no paradoxers, but I was speaking of old time.
This science has slept until our own day: Hamilton[707] says there has been
"no progress made in {332} the _general_ development of the syllogism since
the time of Aristotle; and in regard to the few _partial_ improvements, the
professed historians seem altogether ignorant." But in our time, the
paradoxer, the opponent of common opinion, has appeared in this field. I do
not refer to Prof. Boole,[708] who is not a _paradoxer_, but a
_discoverer_: his system could neither oppose nor support common opinion,
for its grounds were not in the conception of any one. I speak especially
of two others, who fought like cat and dog: one was dogmatical, the other
categorical. The first was Hamilton himself--Sir William Hamilton of
Edinburgh, the metaphysician, not Sir William _Rowan_ Hamilton[709] of
Dublin, the mathematician, a combination of peculiar genius with
unprecedented learning, erudite in all he could want except mathematics,
for which he had no turn, and in which he had not even a schoolboy's
knowledge, thanks to the Oxford of his younger day. The other was the
author of this work, so fully described in Hamilton's writings that there
is no occasion to describe him here. I shall try to say a few words in
common language about the paradoxers.
Hamilton's great paradox was the _quantification of the predicate_; a
fearful phrase, easily explained. We all know that when we say "Men are
animals," a form wholly unquantified in phrase, we speak of _all_ men, but
not of all animals: it is _some or all_, some may be all for aught the
proposition says. This some-may-be-all-for-aught-we-say, or _not-none,_ is
the logician's _some_. One would suppose {333} that "all men are some
animals," would have been the logical phrase in all time: but the predicate
never was quantified. The few who alluded to the possibility of such a
thing found reasons for not adopting it over and above the great reason,
that Aristotle did not adopt it. For Aristotle never ruled in physics or
metaphysics _in the old time_ with near so much of absolute sway as he has
ruled in logic _down to our own time_. The logicians knew that in the
proposition "all men are animals" the "animal" is not _universal_, but
_particular_ yet no one dared to say that _all_ men are _some_ animals, and
to invent the phrase, "_some_ animals are _all_ men" until Hamilton leaped
the ditch, and not only completed a system of enunciation, but applied it
to syllogism.
My own case is as peculiar as his: I have proposed to introduce
mathematical _thought_ into logic to an extent which makes the old stagers
cry:
"St. Aristotle! what wild notions!
Serve a _ne exeat regno_[710] on him!"
Hard upon twenty years ago, a friend and opponent who stands high in these
matters, and who is not nearly such a sectary of Aristotle and
establishment as most, wrote to me as follows: "It is said that next to the
man who forms the taste of the nation, the greatest genius is the man who
corrupts it. I mean therefore no disrespect, but very much the reverse,
when I say that I have hitherto always considered you as a great logical
heresiarch." Coleridge says he thinks that it was Sir Joshua Reynolds who
made the remark: which, to copy a bull I once heard, I cannot deny, because
I was not there when he said it. My friend did not call me to repentance
and reconciliation with the church: I think he had a guess that I was a
reprobate sinner. My offences at that time were but small: I went on
spinning syllogism systems, all alien from the common logic, until I had
six, the initial letters of which, put together, from the {334} names I
gave before I saw what they would make, bar all repentance by the words