This book is a guided tour of the philosophy of biology, canvassing three broad areas: the early history of biology, from Aristotle to Darwin; traditional debates regarding species, function, and units of selection; and recent efforts to better understand the human condition in light of evolutionary biology. Topics are addressed using no more technical jargon than necessary, and without presupposing any advanced knowledge of biology or the philosophy of science on the part of the reader. Discussion questions are also provided to encourage reader reflection.