In this paper, we discuss a unit on Symbolic Logic which has been designed in the context of a course entitled "Mathematics from a Humanist Perspective." The challenge of such a unit is that it must keep a light tone, avoid the use of heavy deductive machinery, and have relevance in the eyes of students. The objective of the unit is to bring about an understanding of the process of formal reasoning by using deductive rules which are elementary and well motivated. This paper contains two innovations: First, we have devised a deductive system which is very easy to use. A second innovative feature is the introduction of natural-language logic puzzles whose translation into symbols is quite straightforward, and whose solution by symbolic processing is easier to carry out than a solution by verbal reasoning. This last fact is especially useful in demonstrating the value of formal reasoning to students.