Of Bodies.

A body is that being which hath these three dimensions, breadth, depth, and length; — or a bulk which makes a sensible resistance; — or whatsoever of its own nature possesseth a place.

Plato saith that it is neither heavy nor light in its own nature, when it exists in its own place; but being in the place where another should be, then it has an inclination by which it tends to gravity or levity.

Aristotle saith that, if we simply consider things in their own nature, the earth only is to be judged heavy, and fire light; but air and water are on occasions heavy and at other times light............