Aristotle
exterior sphere of the Kosmos (the _Aplan=es_) with the countless
number of fixed stars fastened into it, was a type of regularity and
uniformity; eternal and ever moving in the same circular orbit, by
necessity of its own nature, and without any potentiality of doing
otherwise. But the earth and the elemental bodies, organized and
unorganized, below the lunar sphere and in the interior of the
Kosmos, were of inferior perfection and of very different nature.
They were indeed in part governed and pervaded by the movement and
influence of the celestial substance within which they were
comprehended, and from which they borrowed their Form or constituent
essence; but they held this Form implicated with Matter, _i.e._ the
principle of potentiality, change, irregularity, generation, and
destruction, &c. There are thus in these sublunary bodies both
constant tendencies and variable tendencies. The _constant_ Aristotle
calls 'Nature;' which always aspires to Good, or to perpetual
renovation of Forms as perfect as may be, though impeded in this work
by adverse influences, and therefore never producing any thing but
individuals comparatively defective and sure to perish. The
_variable_ he calls 'Spontaneity' and 'Chance,' forming an
independent agency inseparably accompanying Nature--always modifying,
distorting, frustrating, the full purposes of Nature. Moreover, the
different natural agencies often interfere with each other, while the
irregular tendency interferes with them all. So far as Nature acts,
in each of her distinct agencies, the phenomena before us are regular
and predictable; all that is uniform, and all that (without being
quite uniform) recurs usually or frequently, is her work. But,
besides and along with Nature, there is the agency of Chance and
Spontaneity, which is essentially irregular and unpredictable. Under
this agency there are possibilities both for and against; either of
two alternative events may happen.
It is with a view to this doctrine about the variable kosmical
agencies or potentialities that Aristotle lays down the logical
doctrine now before us, distinguishing propositions affirming
particular facts past or present, from propositions affirming
particular facts future. In both cases alike, the disjunctive
antithesis, as a whole, is necessarily true. Either there was a
sea-fight yesterday, or there was not a sea-fight yesterday: Either
there will be a sea-fight to-morrow, or there will not be a sea-fight
to-morrow--both these disjunctives alike are necessarily true. There
is, however, a difference between the one disjunctive couple and the
other, when we take the affirmation separately or the negation
separately. If we say, There will be a sea-fight to-morrow, that
proposition is not necessarily true nor is it necessarily false; to
say that it is either the one or the other (Aristotle argues) would
imply that every thing in nature happened by necessary agency--that
the casual, the potential, the _may be or may not be_, is stopped out
and foreclosed. But this last is really the case, in regard to a past
fact. There was a sea-fight yesterday, is a proposition either
necessarily true or necessarily false. Here the antecedent agencies
have already spent themselves, blended, and become realized in one or
other of the two alternative determinate results. There is no
potentiality any longer open; all the antecedent potentiality has
been foreclosed. The proposition therefore is either necessarily true
or necessarily false; though perhaps we may not know whether it is
the one or the other.
In defending his position regarding this question, Aristotle denies
(what he represents his opponents as maintaining) that all events
happen by necessity. He points to the notorious fact that we
deliberate and take counsel habitually, and that the event is
frequently modified, according as we adopt one mode of conduct or
another; which could not be (he contends), if the event could be
declared beforehand by a proposition necessarily or determinately
true. What Aristotle means by _necessity_, however, is at bottom
nothing else than constant sequence or conjunction, conceived by him
as necessary, because the fixed ends which Nature is aiming at can
only be attained by certain fixed means. To this he opposes
Spontaneity and Chance, disturbing forces essentially inconstant and
irregular; admitting, indeed, of being recorded when they _have_
produced effects in the past, yet defying all power of prediction as
to those effects which they _will_ produce in the future. Hence
arises the radical distinction that he draws in Logic, between the
truth of propositions relating to the past (or present) and to the
future.
But this logical distinction cannot be sustained, because his
metaphysical doctrine (on which it is founded) respecting the
essentially irregular or casual, is not defensible. His opponents
would refuse to grant that there is any agency essentially or in
itself irregular, casual, and unpredictable.[21] The aggregate of
Nature consists of a variety of sequences, each of them constant and
regular, though intermixed, co-operating, and conflicting with each
other, in such manner that the resulting effects are difficult to
refer to their respective causes, and are not to be calculated
beforehand except by the highest scientific efforts; often, not by
any scientific efforts. We must dismiss the hypothesis of Aristotle,
assuming agencies essentially irregular and unpredictable, either as
to the past or as to the future. The past has been brought about by
agencies all regular, however multifarious and conflicting, and the
future will be brought about by the like: there is no such
distinction of principle as that which Aristotle lays down between
propositions respecting the past and propositions respecting the
future.
[Footnote 21: The Stoics were opposed to Aristotle on this point.
They recognized no logical difference in the character of the
Antiphasis, whether applied to past and present, or to future.
Nikostratus defended the thesis of Aristotle against them. See the
Scholia of Simplikius on the Categoriæ, p. 87, b. 30-p. 88, a. 24.
[Greek: ai( ga\r ei)s to\n me/llonta chro/non e)gklino/menai
prota/seis ou)/te a)lêthei=s ei)si\n ou)/te pseudei=s dia\ tê\n tou=
e)ndechome/nou phu/sin.]
The remarks of Hobbes, upon the question here discussed by Aristotle,
well deserve to be transcribed (De Corpore, part II. ch. X. s. 5):--
"But here, perhaps, some man may ask whether those future things,
which are called _contingents_, are necessary. I say, therefore, that
generally all contingents have their necessary causes, but are called
contingents in respect of other events, upon which they do not
depend; as the rain, which shall be to-morrow, shall be necessary,
that is, from necessary causes; but we think and say, it happens by
chance, because we do not yet perceive the causes thereof, though
they exist now. For men commonly call that _casual_ or _contingent_,
whereof they do not perceive the necessary cause; and in the same
manner they use to speak of things past, when not knowing whether a
thing be done or no, they say, it is possible it never was done.
"Wherefore, all propositions concerning future things, contingent or
not contingent--as this, _It will rain to-morrow_, or this,
_To-morrow the sun will rise_--are either necessarily true, or
necessarily false; but we call them contingent, because we do not yet
know whether they be true or false; whereas their verity depends not
upon our knowledge, but upon the foregoing of their causes. But there
are some, who, though they confess this whole proposition, _To-morrow
it will either rain or not rain_, to be true, yet they will not
acknowledge the parts of it, as _To-morrow it will rain_, or
_To-morrow it will not rain_, to be either of them true by itself;
because they say neither this nor that is true _determinately_. But
what is this _determinately true_, but true _upon our knowledge_, or
evidently true? And therefore they say no more, but that it is not
yet known whether it be true or no; but they say it more obscurely,
and darken the evidence of the truth with the same words with which
they endeavour to hide their own ignorance."
Compare also the fuller elucidation of the subject given by Mr. John
Stuart Mill, in his System of Logic, Bk. III. ch. xvii. s. 2:--"An
event occurring by chance may be better described as a coincidence
from which we have no ground to infer an uniformity; the occurrence
of an event in certain circumstances, without our having reason on
that account to infer that it will happen again in those
circumstances. This, however, when looked closely into, implies that
the enumeration of the circumstances is not complete. Whatever the
fact was, since it has occurred once, we may be sure that if all the
circumstances were repeated, it would occur again; and not only if
all, but there is some particular portion of those circumstances, on
which the phenomenon is invariably consequent. With most of them,
however, it is not connected in any permanent manner: its conjunction
with those is said to be the effect of chance, to be merely casual.
Facts casually conjoined are separately the effect of causes, and
therefore of laws; but of different causes, and causes not connected
by any law. It is incorrect then to say that any phenomenon is
produced by chance; but we may say that two or more phenomena are
conjoined by chance, that they co-exist or succeed one another only
by chance."]
There is, indeed, one distinction between inferences as to the past
and inferences as to the future, which may have contributed to
suggest, though it will not justify, the position here laid down by
Aristotle. In regard to the disjunctive--To-morrow there will be a
sea-fight, or there will not be a sea-fight--nothing more trustworthy
than inference or anticipation is practicable: the anticipation of a
sagacious man with full knowledge is more likely to prove correct
than that of a stupid man with little knowledge; yet both are alike
anticipations, unverifiable at the present moment. But if we turn to
the other disjunctive--Yesterday there was a sea-fight, or there was
not a sea-fight--we are no longer in the same position. The two
disputants, supposed to declare thus, may have been far off, and may
have no other means of deciding the doubt than inference. But the
inference here is not unverifiable: there exist, or may exist,
witnesses or spectators of the two fleets, who can give direct
attestation of the reality, and can either confirm or refute the
inference, negative or affirmative, made by an absentee. Thus the
proposition, Yesterday there was a sea-fight, or the other, Yesterday
there was not a sea-fight, will be verifiable or determinably true.
There are indeed many inferences as to the past, in regard to which
no direct evidence is attainable. Still this is an accident; for such
direct evidence may always be supposed or imagined as capable of
being brought into court. But, in respect to the future, verification
is out of the question; we are confined to the region of inference,
well or ill-supported. Here, then, we have a material distinction
between the past and the future. It was probably present to the mind
of Aristotle, though he misconceives its real extent of operation,
and makes it subservient to his still more comprehensive
classification of the different contemporaneous agencies (regular and
irregular) which he supposes to pervade the Kosmos.
In the treatise before us, he next proceeds to state what collocation
of the negative particle constitutes the special or legitimate
negation to any given affirmation, or what are the real forms of
proposition, standing in contradictory opposition to certain other