I recommend this book to philosophy students who study philosophical logic and wish to get into mathematical logic. The system of natural deduction he uses is not explained in much detail, but as long as you have learned at least one system of natural deduction and perhaps even the tree method of proof, you should be fine. His definitions and explanations of terms and of how one develops logical rules are excellent and explained very well. There is also a treatment of informal proof methods that mathematicians use, a section on basic set theory, and a section on axiomatizing scientific theories--the latter hinting at some of Suppes' own philosophical ideas.