Henry Laycock talks about his past and current work on plural and mass terms and their history. He begins by informally explaining the logical and metaphysical differences between singular, plural, and mass terms. He then discusses why post-Quinean first-order predicate logic and its correlate theory of reference cannot account for the non-singular, emphasizing crucially the non-referential use of bare non-singular nouns. Laycock then considers how we got to this point, given that some ancient Greek philosophers were attuned to these issues. He identifies the source of the difficulty in Aristotle's atomistic logic and traces its continuation through the scientific revolution to our present-day conceptions of logic. He then addresses a challenge to his view, according to which mass terms, like 'water', ought to be understood as referring simply to molecules – the problem is simply raised to a higher level, since irreducibly non-singular sentences, whether mass or plural, denote essentially 'bulk' or 'aggregate' phenomena. He ends by considering how linguistics has greatly enriched philosophical work on mass nouns and the non-singular. Henry Laycock is Emeritus Professor of Philosophy at Queen's University.