 The obvious question now is: if all knowledge is ultimately based on acquaintance, what is it we can be acquainted with, i.e., what are the legitimate objects of acquaintance? Because, according to Russell, the acquaintance relation is a relation to individual things this question translates into “what are the individual things we can be acquainted with?” Russell’s answer to this question is that there are exactly two kinds of things we can be acquainted with, namely particulars, i.e., things that exist, and universals, i.e., things that subsist (cf. 1912 [1974: 100]). Particulars comprise sense-data, thoughts, feelings, desires and memories of “things which have been data either of the outer senses or of the inner sense” (1912 [1974: 51]). Universals are