The ancient Roman orator Horace (65 B.C.–8 B.C.) wrote, "Control your mind or it will control you." In today's society we are faced with more information, and more complex information, than ever. Faced with making decisions, we can feel overwhelmed and helpless. One way to become less helpless — to gain control over our lives — is to gain control over our own thinking. We can feel helpless when faced with this barrage of information, opinions, data, and conflicting arguments if we lack the skills to quickly grasp and critically evaluate them. This book is designed to impart these kinds of skills. Any course in a university should do more than teach information — in nearly every field, 'facts' become obsolete quickly. The goals of Thinking Matters are to help you: to be more creative, fluid, and perceptive in solving problems; to identify the implicit premises, fallacies, or moral principles that are presupposed in the arguments of others; to be able to advocate for what you believe by effectively refuting opposing arguments and presenting persuasive arguments of your own; to understand the logic of scientific testing to distinguish between science and pseudo-science; to develop your own style and intuitive powers of logical deduction, probabilistic reasoning, and computational thinking. The text is punctuated with exercises or 'personal experiments' to challenge and stimulate your curiosity. These exercises may take the form of an inventory to be taken, a puzzle to be solved, or some thoughts to ponder. The first module Thinking Matters: Critical Thinking as Creative Problem Solving introduces the student to all the above topics — logic, probability, argument forms and fallacies, ethical reasoning, algorithms, and computational thinking — through logic puzzles and games and mathematical magic tricks.