actual water. Copper and gold are not formed like that, but in every
case the evaporation congealed before water was formed. Hence, they
all (except gold) are affected by fire, and they possess an
admixture of earth; for they still contain the dry exhalation.
This is the general theory of all these bodies, but we must take
up each kind of them and discuss it separately.
WE have explained that the qualities that constitute the elements
are four, and that their combinations determine the number of the
elements to be four.
Two of the qualities, the hot and the cold, are active; two, the dry
and the moist, passive. We can satisfy ourselves of this by looking at
instances. In every case heat and cold determine, conjoin, and
change things of the same kind and things of different kinds,
moistening, drying, hardening, and softening them. Things dry and
moist, on the other hand, both in isolation and when present
together in the same body are the subjects of that determination and
of the other affections enumerated. The account we give of the
qualities when we define their character shows this too. Hot and
cold we describe as active, for 'congregating' is essentially a
species of 'being active': moist and dry are passive, for it is in
virtue of its being acted upon in a certain way that a thing is said
to be 'easy to determine' or 'difficult to determine'. So it is
clear that some of the qualities are active and some passive.
Next we must describe the operations of the active qualities and the
forms taken by the passive. First of all, true becoming, that is,
natural change, is always the work of these powers and so is the
corresponding natural destruction; and this becoming and this
destruction are found in plants and animals and their parts. True