Tahafut_al-Tahafut-transl-Engl-van-den-Bergh

I say:
says that the lamp makes the light and the man makes the
shadow uses the term vaguely, giving it a sense much wider
than its definition, and uses it metaphorically, relying on the
fact that there is an analogy between the object originally
meant by it and the object to which it is transferred, i.e. the
agent is in a general sense a cause, the lamp is the cause of
the light, and the sun is the cause of luminosity; but the
agent is not called a creative agent from the sole fact that it
is a cause, but by its being a cause in a special way, namely
that it causes through will and through choice. If, therefore,
one said that neither a wall, nor a stone, nor anything
inanimate is an agent, and that only animals have actions,
this could not be denied and his statement would not be
called false. But according to the philosophers a stone has
an action, namely falling and heaviness and a centripetal
tendency, just as fire has an action, namely heating, and a
wall has an action, namely a centripetal tendency and the
throwing of a shadow, and, according to them each of these
actions proceeds from it as its agent; which is absurd.’
There are in brief two points here, the first of which is that only those
who act from deliberation and choice are regarded as acting causes, and
the action of a natural agent producing something else is not counted
among acting causes, while the second point is that the philosophers
regard the procession of the world from God as the necessary connexion
obtaining between shadow and the person, and luminosity and the sun,
and the downward rolling in relation to the stone, but that this cannot be
called an action because the action can be separated from the agent.
I say:
All this is false. For the philosophers believe that there are four causes:
agent, matter, form, and end. The agent is what causes some other thing
to pass from potency to actuality and from nonexistence to existence; this
actualization occurs sometimes from deliberation and choice, sometimes
by nature, and the philosophers do not call a person who throws a shadow
an agent, except metaphorically, because the shadow cannot be
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