68. Chemistry
Chemistry deals with things seen as small or basic finalities. It deals with these things as parts. Physics deals with things as wholes.
An element is seen as a basic thing; that is, as a finality of physical or weight-existence. The element is seen as a part of substances. The element is a certain kind of finality.
An atom in chemistry is seen as a phase or part of an element. The important thing is, that it is seen as a part; it is what makes the element; it can be seen as within the element.
The atom in physics, to which it equally belongs, is seen as a whole. Physics, as physics, does not deal with the within aspect of physical finalities. Physics deals with what matter does, as wholes; chemistry deals with the constituents of matter.
For example, if an atom of hydrogen collided, as a whole, with an atom of uranium, it would be physics; for the atoms are being seen as independent entities meeting each other, not merging to make something else. But when atoms come together for the purpose of becoming a one, a larger one including them, chemistry is taking place.
The essential difference between chemistry and physics is that the first deals with things as belonging to something; the second, with things as independent or wholes in their own right.
For example, in physiology (which is both chemistry and physics), blood thought of as containing certain elements, is of chemistry; blood thought of as being a force, propelling, or a thing propelled, would be of physics.
The elements that make up a leaf are of chemistry; the reason why, under pressure of the wind, a leaf whirls a certain way, is of physics.
The self is both chemical and physical.