Although mathematical ability and opinions about mathematics vary widely, even among educated people, there is certainly widespread agreement that mathematics is logical. Indeed, properly conceived, this may be one of the most important defining properties of mathematics. Logical thought and logical arguments are not easy to come by (ponder some of the discussions you encounter on current topics such as abortion, climate change, evolution, gun control, or same sex marriage to appreciate this statement), nor is it always clear whether a given argument is logical (that is, logically correct). Logic itself deserves study; the right tools and concepts can make logical arguments easier to discover and to discern. In fact, logic is a major and active area of mathematics; for our purposes, a brief introduction will give us the means to investigate more traditional mathematics with confidence.