ness
supervenes, we can call effort, an activity, even though, at its best,
only an imperfect activity. He looks up at the splendour of the circling
stars and asks if it is possible that so glorious an order can be
anything but a manifestation of something akin to the divine. Here
indeed he is speaking of movements made by existences he reckoned among
the highest in the world, for he thought the stars were living beings
higher than man. But he recognized a rudimentary form of such activity
even in what we now call inanimate matter. Here we come to a leading
conception of Aristotle's, and one most important for our purpose: the
conception of a hierarchy of natural existences, all of them with some
value, less or more. When Aristotle is truest to himself, he will tell
us not to be afraid of studying the meanest forms of natural existence,
because in everything there is something marvellous and divine. He
quotes with much satisfaction the story of Heracleitus, who welcomed
his friends into the bakehouse with the saying that 'there were gods in
the bakehouse too'.[17]

Thus, at the lowest end of the scale, we have what we call inanimate
matter, which Aristotle thinks of much as we do, namely, as something
occupying space, the different parts of it being endowed with different
powers of movement, and with different properties, such as warmth or
coldness, wetness or dryness. A natural thing, he says, is a thing that
has a principle of activity in itself, something that makes it act in a
definite way, whenever it is not interfered with by anything else.[18]
Aristotle speaks, for example, of fire having a natural tendency to
mount up, much as we might speak of solids having a natural tendency to
gravitate towards one another. Go back as far as we like, and, Aristotle
thinks, we still find certain primitive differences which constitute
what we call the primitive elements. This, I imagine, is much the point
of view of modern science.

And these primitive elements in Aristotle's view influence each other,
unite with each other, or change into each other. As a rule, however,
they exhibit no new powers. But given a happy concurrence of qualities,
say a certain union of heat and cold, and a new power does become
manifest: the power of life. Thus, in a sense, Aristotle does envisage
the spontaneous generation of life; and he knows, roughly, what he means
by life. The living thing can go through far more changes than the
non-living,