  One way in which Berkeley’s anti-abstractionism comes into play is in reinforcing this point. Berkeley argues in the “Introduction” to the  Principles[1]  that we cannot form general ideas in the way that Locke often seems to suggest—by stripping particularizing qualities from an idea of a particular, creating a new, intrinsically general, abstract  idea.[2]  Berkeley then claims that notions the materialist might invoke in a last-ditch attempt to characterize matter, e.g. being or mere extension, are objectionably abstract and  unavailable.[3]