Arguments are one way we have of coming to know about our world. We make arguments about philosophical topics like the existence of God, but also about mundane things like the best way to drive from Philadelphia to New York. The goal of these notes is to provide tools for understanding, constructing, and dismantling arguments. Some of the tools introduced are *formal*. That just means the things you write out might look a bit like mathematics. This is not a formal logic course, however. We use tools from formal logic in much the way that physicists use tools from math: to help understand and solve problems. These notes thus use logical tools in a mercenary fashion, as models of stuff that goes on in ordinary language. They are the result of teaching a course on the topic over the last six years or so, since I couldn’t find a text that did things the way I wanted them done. If you are looking for a more traditional logic course, which develops the formalism as an introduction to a branch of mathematics, I recommend PD Magnus’s forallx, an excellent introductory, open-access text. So far, this course is incomplete, but I hope to add more over the years.

Work through the files below in order. Later ones depend on the earlier ones. The problems correspond to different groups of notes. They are useless unless you try to solve them before looking at the answers.

All of the notes and problems here are available under a Creative Commons BY-SA 3.0 license. Have fun, and if you have questions or comments, just send me an email. I plan on updating these notes over the years, with the ultimate goal being an open access textbook on the topic.