You have probably heard or read that a certain bird's beak was "designed" to crack nuts or catch insects, or that the eye is "designed" to focus light. This manner of speaking seems to imply that we all believe or accept that evolution has a purpose, that it might even have a designer. This book examines these habits of language to explore whether evolution really can be said to have a purpose.
The author begins by examining the history of the philosophical subject of "final causes", wherein a future event is said to "cause" a current event, like a student taking a course (current event) because she plans to earn a certain degree (future cause). He then moves on to a history of evolution, with a particular focus on final causes leading organisms to become more and more complex. One thing I learned is that Darwin didn't "invent" evolution. The idea that life forms evolved into different forms had been around and generally accepted for some decades. What Darwin invented was a plausible mechanism in adaptation through natural selection.
In the final chapter or two, the author examines the 20th century conflict between science and religion over evolution, a conflict that was by no means universal in all religious thinking. He gives his opinion, without forcing it on you and expecting you to believe the same.
This is largely a work of philosophy, and although it is easier to read than other philosophical works I have read, it still requires effort and attention to follow the arguments and the chains of reasoning. The author has a tendency to assume that you remember points made and historical figures mentioned dozens of pages ago, a habit that can add to the difficulty if you take long breaks between reading sessions.
Overall, I found this a thought-provoking book and an eye-opener to the subtler-than-expected nuances in arguments for and against purpose in evolution.