The focus of this paper will be on certain aspects of three concepts, those of existence, explanation, and force, together with some related ideas. Specifically, I want to look at some of the roots of those concepts both in written history and, somewhat speculatively, in more primitive circumstances of the history of the human species; and I want to compare certain aspects of the three concepts with their rational descendants in the theories and expectations of contemporary physics. Although these topics are interesting and important in themselves, and there is much more to say about them, my primary aim in the present essay will be to extract some methodological implications from them regarding the problems and methods of the philosophy of science. Indeed, some of the ways in which the topics are important for philosophers of science will be brought out by the discussion of those methodological implications.