There is a form of philosophical perplexity that arises out of knowledge and that is an essential precondition for philosophizing. I found myself in that condition when I first encountered Bishop Berkeley's apparent demonstration of the “impossibility that the objects around me should have any existence out of the minds or thinking things that perceive them”.

But there is another kind of perplexity, which I often felt as a beginning student, and which I often still feel: a perplexity that arises out of a lack of knowledge, that must be remedied if philosophy is to be done at all. Often I hear names mentioned, with a certain reverence, by those who purport to be insiders; mentioned, moreover, with the implication that anyone interested in philosophy will be on easy nodding terms with the deliberations of the bearers of those names. And of those names and their associated deliberations I am quite ignorant. Sometimes, of course, the names aren't that important, being instances of that law of propinquity by which graduate students are fated to overestimate their supervisors. More often the names are important, and knowledge of the deliberations of their bearers is a prerequisite for engaging in philosophy.

Where such names are rooted in the history of the subject, overcoming ignorance is easy. Histories of philosophy abound. When we come to contemporary philosophy, and to its influential figures, matters become more difficult.