This course is an introduction to critical thinking with a primary focus on the principles of argumentation. We will ask: what makes an argument good or bad, reasonable or unreasonable? How should one go about evaluating an argument? Philosophers have developed a handy toolkit for handling such questions, which this course will familiarize you with. The philosopher’s toolkit includes a taxonomy of standard valid and invalid argument forms, as well as some common mistakes that people make when making arguments. It also includes skills for dealing with the ‘informal’ aspects of arguments, beyond what is strictly contained in their formal structure. This includes tools for evaluating an argument’s inductive strength and plausibility of an argument’s premises, and for distinguishing an argument’s logical strength from its rhetorical force. Here, questions about the content of our concepts, and their context of use, become particularly relevant. As we’ll see, in the messy world of informal reasoning no strategy is infallible. However, you will learn a variety of techniques which will be useful across your academic, professional, and personal lives.