Philip Bold, Dept. of Philosophy, University of Minnesota, Twin Cities—Philosophical Investigations 47 offers a compelling critique of the metaphysical notion of ‘absolute simples’—either of language, reality, or of (visual) experience. In short: since any distinction between ‘simple’ and ‘composite’ is relative to how we (inter-)define those terms, and many such definitions are available to us in any given case, there is no ‘absolute’ notion of ‘simple’ or ‘composite’. 

To what extent does this critique of philosophical atomism bear on the common distinction between ‘simple’ and ‘complex’ elements of experience in early modern empiricism? I investigate this question with a particular focus on Hume's proposed “science of human nature”. The bearing of Investigations 47 on Hume largely depends on our understanding of his project—an interpretive question that has received relatively little attention. Namely: is Hume’s distinction between ‘simple’ and ‘complex’ ideas/impressions intended to follow from the phenomenology of our experience or is it instead a theoretical stipulation with specific explanatory or pragmatic aims? If the former, then the critique found in Investigations 47 is devastating for Hume’s theory, as ‘experience itself’ is compatible with many such ways of distinguishing ‘simple’ and ‘complex’ elements; but if the latter, then Hume may have anticipated the problem raised by Wittgenstein and would (perhaps) justify his theoretical stipulations on pragmatic grounds.