Ed Feser has a great dissection of the “Nothing but…” approach to philosophy and science.
And that is, of course, exactly what the “mechanical” conception of the world that the early modern philosophers put in place of the Scholastics’ Aristotelian philosophy of nature made possible. The world was reconceived as a machine or collection of machines. Break a natural object down into its parts and identify the efficient-causal relations holding between them, and you know (so the moderns claim) everything there is to know about its intrinsic nature. Anything irreducible to this – such as final causality or end-directedness, or a “formal cause” over and above the sum of the parts – is extrinsic to it, observer-relative, whether the observer is a human being or a divine artificer. For Aristotle, “art imitates nature” – that is to say, artifacts copy nature’s way of doing things, but only (of course) artificially since their parts have no inherent tendency to do what we make them do. The moderns reverse this – nature is for them a kind of “art,” in the sense that natural objects are to be modeled on artifacts rather than the other way around.