First, given criteria for identifying universals and particulars, it is shown that stuffs appear to qualify as neither. Second, the standard solutions to the logico-linguistic problem of mass terms are examined and evidence is presented in favor of the view that mass terms are straightforward singular terms and, relatedly, that stuffs indeed belong to a metaphysical category distinct from the categories of universal and particular. Finally, a new theory of the copula is offered: 'The cue is cold', 'The cube is ice', and 'Ice is water' all have the form 'A is B'. On the basis of the logical behavior of stuff-names with respect to this univocal copula, definitions are suggested for 'X is a stuff', 'X composes Y', 'X is a material object', and even 'Matter'. Hence an expanded form of logicism.