'What Does It All Mean?' is a brief introduction to philosophy by the American philosopher Thomas Nagel. It was originally published in 1987. The author states in his introduction that he intends the book to be useful for complete beginners, particularly adults, but the text is clearly written and should be accessible to intelligent teenagers.
Nagel believes that philosophy originates in certain questions that human beings have asked of themselves repeatedly. Accordingly, he divides his text into nine chapters, each of which deals with a single problematical issue. The idea is to give the novice reader a taste of the issues with which philosophy concerns itself, and its style of critical thinking, without encumbering him or her with the need to be familiar with historical philosophical movements, specific philosophers, or specialist terminology beyond the minimum for meaningful discussion.
In itself, the book is easily recommended. My only reservations concern value for money. The book is expensive for what is really an essay-length monograph (less than 25,000 words in total, or 100 pages of text). While it may seem unphilosophical to question whether wisdom has a price, this is a book aimed at "college-age" readers, and there are now several excellent introductions to the subject by well-known professional philosophers that are more recent, cheaper and more extensive in their coverage. The interested reader is in any case likely to have to supplement the Nagel with further reading; but will have to look elsewhere for suggestions, as Nagel makes none. (The book appears not to have been updated since its original appearance.) At the time of review, the Kindle edition is significantly better value.