The word clear has different meanings, but fundamentally it gets at the idea that an exposition is "bright", "full of light" -- that is, it brings its subject out into the light where we can get a good look at it. This in contrast with the obscure, which withdraws its subject matter and itself back into the shadows. Perhaps it would not be ironic to say that all philosophical writing aims at clarity, but there is an especial difficulty in the achievement because of this peculiarity of language -- that whatever it shows it also hides -- that is, whatever it clears it obscures.

Aside from wondering what all of this may have to do with a short book entitled "What Does It All Mean?", you may notice that part of the problem is that the distinction between clear / obscure is not itself clear. This is the kind of thing that Nagel wants us to think about while reading his book: what does it mean to make a distinction and what kinds of distinctions about the world are accurate -- that is, hit the boundaries between things and ideas on the mark?

So while each of his chapters *seems* to cover a "philosophical problem", we often find that the real subject of each chapter, and of the book as a whole, is whether the distinctions we commonly make between phenomena are valid distinctions. "Am I inside myself, and if I am inside of myself, am I inside myself in a different way than my brain is inside my head?" -- this is at issue in the chapter on "The Mind/Body Problem". "What distinguishes my mind from the minds of other people? What distinguishes consciousness from unconsciousness?" -- these are the questions Nagel looks at in his chapters on "Death" and "Other Minds". And of course, the perennial "Does the world really exist outside my experience?" is easily seen to participate in the same problematic attempt to distinguish inside from outside, right from wrong, self from other, etc.

One might be tempted to ask, after reading this book, whether it is not the distinctions themselves that are, in each case, the problem, and become taken with the peculiar idea that, if only we stopped making distinctions, we would stop having problems. On the contrary, it seems a certain amount of distinction between the phenomena presented to our senses (and present in our thought) is necessary to live in the world. The goal of philosophy, I suppose, is to minimize the damage. Nagel's book is one such exercise in this kind of "damage control". ( )