ABSTRACT
In the introduction of the Principles of human knowledge, Berkeley attacks abstract general ideas. He finds that the process or operation of abstracting and the alleged products of such an operation highly problematic, and thus he concludes that neither the process nor the product actually occurs or exists. Establishing that Berkeley is right about is, certainly, too big a task to be completed here. But some idea of the plausibility of such a statement can be easily gotten when one reflects that the esse is percipi thesis is itself essential to many of Berkeley’s further central doctrines; hence, by a sort of simple transitivity, would thereby have shown that Berkeley would be on pretty safe ground in endorsing. The possession of the right sort of abstract general idea is both necessary and sufficient for the possibility of conceiving of a sensible object existing unperceived.
