PHYSICS by Aristotle Public Domain English Translation by R. P.
Hardie and R. K. Gaye When the objects of an inquiry, in any
department, have principles, conditions, or elements, it is
through acquaintance with these that knowledge, that is to say
scientific knowledge, is attained. For we do not think that we
know a thing until we are acquainted with its primary conditions
or first principles, and have carried our analysis as far as its
simplest elements. Plainly therefore in the science of Nature,
as in other branches of study, our first task will be to try to
determine what relates to its principles. The natural way of
doing this is to start from the things which are more knowable
and obvious to us and proceed towards those which are clearer
and more knowable by nature; for the same things are not
'knowable relatively to us' and 'knowable' without
qualification. So in the present inquiry we must follow this
method and advance from what is more obscure by nature, but
clearer to us, towards what is more clear