It is suggested that the view which considers the approach of chemistry reducible to that of physics is not correct. Chemistry explains the properties of materials in terms of special entities, the molecules; hence, in its descent toward the extremely small, it stops at a certain level of complexity, and adopts an “ontological” point of view; which implies the introduction of unique structural concepts, such as the chemical bond. Historical considerations confirm the view that chemistry is complementary to physics. Physics (...) proper retains a special status insofar as it seeks explanations in term of motion governed by first principles; but by the same token it provides only partial answers to scientific inquires. (shrink)