With thy diurnal swegh that croudest ay,
And hurtlest all from Est til Occident,
That naturally wold hold another way,"

without some knowledge of the astronomy of his day?

Our first extracts explain themselves. They deal with the mystery of
the constitution of substances, as fascinating to us as to the early
Greeks, and begin with definitions of matter and form.

The principal design of early philosophers in physics was to explain
how everything was generated, and to trace the different states
through which things pass until they become perfect. They observed
that as a thing is not generated out of any other indifferently--for
example, that marble is not capable of making flesh, all bodies cannot
be compounded of principles alone, connected in a simple way, but
imagined they could be made up of a few simple compounds. These
ultimate compounds, if we may so express it, were their elements. The
number of elements was variously estimated, but was generally taken as
four--a number arrived at rather from the consideration of the
sensations bodies awaken in us, than from the study of bodies
themselves. Aristotle gives us the train of thought by which the
number is reached. He considers the qualities observed by the senses,
classifying them as Heat, Cold, Dryness or Hardness, and Moistness or
Capability of becoming liquid. These may partially co-exist, two at a
time, in the same substance. There are thus four possible
combinations, Cold and dry, Cold and moist, Hot and dry, Hot and
moist. He then names these from their prototypes Earth, Water, Fire,
and Air, distinguishing these elements from the actual Earth, etc., of
everyday life.