In order to understand the Scientific Revolution, it is essential for students to understand the new ways of scientific thinking that surfaced during the 17th century. Deductive reasoning, which uses general premises to arrive at a certain conclusion, has been around since Aristotle. In his book Novum Organum, Sir Francis Bacon advanced a new way of philosophical inquiry known as inductive reasoning, in which the inquirer comes to a probable conclusion based on n several specific observations. While inductive reasoning is typically most closely associated with the scientific method, inductive reasoning has not lost its value. Rene Descartes famous phrase, "Cogito Ergo Sum," is in itself a process of induction. I present several examples of deductive and inductive reasoning, including Aristotle's classic, "All men are mortal... Socrates is a man... Socrates is mortal." I also explore the so-called "problem of induction" noted by critics such as David Hume. Although induction cannot lead to certain truth, it was never meant to lead to certain truth. Although I designed this lecture for my AP European History students, it can also be useful for those studying philosophy, communication, logic, and the scientific method.