Whether Heavenly Bodies Impose Necessity on Things Subject to Their
Action?
Objection 1: It would seem that heavenly bodies impose necessity on
things subject to their action. For given a sufficient cause, the
effect follows of necessity. But heavenly bodies are a sufficient
cause of their effects. Since, therefore, heavenly bodies, with their
movements and dispositions, are necessary beings; it seems that their
effects follow of necessity.
Obj. 2: Further, an agent's effect results of necessity in matter,
when the power of the agent is such that it can subject the matter to
itself entirely. But the entire matter of inferior bodies is subject
to the power of heavenly bodies, since this is a higher power than
theirs. Therefore the effect of the heavenly bodies is of necessity
received in corporeal matter.
Obj. 3: Further, if the effect of the heavenly body does not follow
of necessity, this is due to some hindering cause. But any corporeal
cause, that might possibly hinder the effect of a heavenly body, must
of necessity be reducible to some heavenly principle: since the
heavenly bodies are the causes of all that takes place here below.
Therefore, since also that heavenly principle is necessary, it
follows that the effect of the heavenly body is necessarily hindered.
Consequently it would follow that all that takes place here below
happens of necessity.
_On the contrary,_ The Philosopher says (De Somn. et Vigil. [*De
Divin. per Somn. ii]): "It is not incongruous that many of the signs
observed in bodies, of occurrences in the heavens, such as rain and
wind, should not be fulfilled." Therefore not all the effects of
heavenly bodies take place of necessity.
_I answer that,_ This question is partly solved by what was said
above (A. 4); and in part presents some difficulty. For it was shown
that although the action of heavenly bodies produces certain
inclinations in corporeal nature, the will nevertheless does not of
necessity follow these inclinations. Therefore there is nothing to
prevent the effect of heavenly bodies being hindered by the action of
the will, not only in man himself, but also in other things to which
human action extends.
But in natural things there is no such principle, endowed with
freedom to follow or not to follow the impressions produced by
heavenly agents. Wherefore it seems that in such things at least,
everything happens of necessity; according to the reasoning of some
of the ancients who supposing that everything that is, has a cause;
and that, given the cause, the effect follows of necessity; concluded
that all things happen of necessity. This opinion is refuted by
Aristotle (Metaph. vi, Did. v, 3) as to this double supposition.
For in the first place it is not true that, given any cause whatever,
the effect must follow of necessity. For some causes are so ordered
to their effects, as to produce them, not of necessity, but in the
majority of cases, and in the minority to fail in producing them. But
that such causes do fail in the minority of cases is due to some
hindering cause; consequently the above-mentioned difficulty seems
not to be avoided, since the cause in question is hindered of
necessity.
Therefore we must say, in the second place, that everything that is
a being _per se,_ has a cause; but what is accidentally, has not a
cause, because it is not truly a being, since it is not truly one.
For (that a thing is) "white" has a cause, likewise (that a man is)
"musical" has not a cause, but (that a being is) "white-musical" has
not a cause, because it is not truly a being, nor truly one. Now it
is manifest that a cause which hinders the action of a cause so
ordered to its effect as to produce it in the majority of cases,
clashes sometimes with this cause by accident: and the clashing of
these two causes, inasmuch as it is accidental, has no cause.
Consequently what results from this clashing of causes is not to be
reduced to a further pre-existing cause, from which it follows of
necessity. For instance, that some terrestrial body take fire in the
higher regions of the air and fall to the earth, is caused by some
heavenly power: again, that there be on the surface of the earth some
combustible matter, is reducible to some heavenly principle. But that
the burning body should alight on this matter and set fire to it, is
not caused by a heavenly body, but is accidental. Consequently not
all the effects of heavenly bodies result of necessity.
Reply Obj. 1: The heavenly bodies are causes of effects that take
place here below, through the means of particular inferior causes,
which can fail in their effects in the minority of cases.
Reply Obj. 2: The power of a heavenly body is not infinite. Wherefore
it requires a determinate disposition in matter, both as to local
distance and as to other conditions, in order to produce its effect.
Therefore as local distance hinders the effect of a heavenly body
(for the sun has not the same effect in heat in Dacia as in
Ethiopia); so the grossness of matter, its low or high temperature or
other such disposition, can hinder the effect of a heavenly body.
Reply Obj. 3: Although the cause that hinders the effect of another
cause can be reduced to a heavenly body as its cause; nevertheless
the clashing of two causes, being accidental, is not reduced to the
causality of a heavenly body, as stated above.
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ON FATE
(In Four Articles)
We come now to the consideration of fate. Under this head there are
four points of inquiry:
(1) Is there such a thing as fate?
(2) Where is it?
(3) Is it unchangeable?
(4) Are all things subject to fate?
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