Cause Principle Unity

On magic
On the bondings of spirits, and first those arising
from the three conditions of agent, matter, and application
For actions actually to occur in the world, three conditions are required:
(1) an active power in the agent; (2) a passive power or disposition in a subject
or patient, which is an aptitude in it not to resist or to render the action
impossible (which reduces to one phrase, namely, the potency of matter);
and (3) an appropriate application, which is subject to the circumstances
of time, place and other conditions.
In the absence of these three conditions, all actions are, simply speaking,
always blocked. For even if a flute player is perfect, he is blocked by a broken
flute, and the application of the former to the latter is useless. Thus, a
lack of power in the matter makes an agent impotent and an application
unfitting. This is what was meant when we said that an absence of these
three conditions, strictly speaking, always blocks an action.
Closer examination may show that the defect is due to only two, or even
only one, of these conditions. But a defect in any one of them should be
understood as meaning a defect in all three, as when the flute player and his
performance are perfect but the flute is defective, or when the player and
the flute are perfect but the performance is interrupted. If the whole
meaning of efficient action is taken to consist in the application, then the
first condition merges with the third, for the agent is nothing other than the
applicator, and to do something is nothing other than to apply something.
Not all things are by nature passive, or active, in relation to all other
things. Rather, as is said in the Physics, 25 every passion is from a contrary,
and every action is on a contrary, or more specifically, on a disposed contrary,
as is stated in the common saying, ‘Active powers act on a properly
disposed patient’. From this, it is clear that water mingles and mixes with
water because of a similarity or awareness or sympathy, such that after they
have united, no device can separate the one from the other.
Indeed, pure or unmingled wine also easily mixes with water, and vice
versa, thus forming a mixture. But the parts of the wine contain some
amount of heat and air and spirits, and thus the wine is not completely
sympathetic with the water. As a result, they do not mix at the smallest level
but survive separately to a noticeable degree in a heterogeneous compound,
so that they can be separated again in various ways. The same thing
25 Aristotle, Physics, I, 5. See also his De generatione et corruptione, I, 7, which makes this point more
explicitly.
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