• Course Introduction

      • Time: 40 hours
      • Free Certificate
      This course will introduce you to critical thinking, informal logic, and a small amount of formal logic. Its purpose is to provide you with the basic tools of analytical reasoning, which will give you a distinctive edge in a wide variety of careers and courses of study. While many university courses focus on the presentation of content knowledge, the emphasis here is on learning how to think effectively. Although the techniques and concepts covered here are classified as philosophical, they are essential to the practice of nearly every major discipline, from the physical sciences and medicine to politics, law, and the humanities.

      The course touches upon a wide range of reasoning skills, from verbal argument analysis to formal logic, visual and statistical reasoning, scientific methodology, and creative thinking. Mastering these skills will help you become a more perceptive reader and listener, a more persuasive writer and presenter, and a more effective researcher and scientist.

      The first unit introduces the terrain of critical thinking and covers the basics of meaning analysis, while the second unit provides a primer in analyzing arguments. All of the material in these first units will be built upon in subsequent units, which cover informal and formal logic, Venn diagrams, scientific reasoning, as well as strategic and creative thinking.

      First, read the course syllabus. Then, enroll in the course by clicking "Enroll me in this course". Click Unit 1 to read its introduction and learning outcomes. You will then see the learning materials and instructions on how to use them.

    • Unit 1: Introduction and Meaning Analysis

      Critical thinking is a broad classification for a diverse array of reasoning techniques. In general, critical thinking works by breaking arguments and claims down to their basic underlying structure so we can see them clearly and determine whether they are rational. The idea is to help us do a better job of understanding and evaluating what we read, what we hear, and what we ourselves write and say.

      In this unit, we will define the broad contours of critical thinking and learn why it is a valuable and useful object of study. We will also introduce the fundamentals of meaning analysis: the difference between literal meaning and implication, the principles of definition, how to identify when a disagreement is merely verbal, the distinction between necessary and sufficient conditions, and problems with the imprecision of ordinary language.

      Completing this unit should take you approximately 5 hours.

    • Unit 2: Argument Analysis

      Arguments are the fundamental components of all rational discourse: nearly everything we read and write, like scientific reports, newspaper columns, and personal letters, as well as most of our verbal conversations contain arguments. Picking the arguments out from the rest of our often convoluted discourse can be difficult. Once we have identified an argument, we still need to determine whether or not it is sound. Luckily, arguments obey a set of formal rules that we can use to determine whether they are good or bad. 

      In this unit, you will learn how to identify arguments, what makes an argument sound as opposed to unsound or merely valid, the difference between deductive and inductive reasoning, and how to map arguments to reveal their structure.

      Completing this unit should take you approximately 7 hours.

    • Unit 3: Basic Sentential Logic

      This unit introduces a topic that many students find intimidating: formal logic. Although it sounds difficult and complicated, formal, or symbolic, logic is actually a fairly straightforward way of revealing the structure of reasoning. By translating arguments into symbols, you can more readily see what is right and what is wrong with them, and you can learn how to formulate better arguments. Advanced courses in formal logic focus on using rules of inference to construct elaborate proofs. Using these techniques, you can solve many complicated problems simply by manipulating symbols on the page. In this course, however, you will only be looking at the most basic properties of a system of logic. In this unit you will learn how to turn phrases in ordinary language into well-formed formulas, draw truth-tables for formulas, and evaluate arguments using those truth-tables.

      Completing this unit should take you approximately 13 hours. 

    • Unit 4: Venn Diagrams

      In addition to using predicate logic, the limitations of sentential logic can also be overcome by using Venn diagrams to illustrate statements and arguments. Statements that include general words like "some" or "few" as well as absolute words like "every" and "all" – so-called categorical statements – lend themselves to being represented on paper as circles that may or may not overlap.

      Venn diagrams are especially helpful when dealing with the logical arguments called syllogisms. Syllogisms are a special type of three-step argument with two premises and a conclusion, which involve quantifying terms. In this unit, you will learn the basic principles of Venn diagrams, how to use them to represent statements, and how to use them to evaluate arguments.

      Completing this unit should take you approximately 6 hours.

    • Unit 5: Fallacies

      Now that you have studied the necessary structure of a good argument and can represent its structure visually, you might think it would be simple to pick out bad arguments. However, identifying bad arguments can be very tricky in practice. Very often what at first appears to be ironclad reasoning turns out to contain one or more subtle errors.

      Fortunately, there are a large number of easily identifiable fallacies – mistakes of reasoning – that you can learn to recognize by their structure or content. In this unit, you will learn about the nature of fallacies, look at a couple of different ways of classifying them, and spend some time dealing with the most common fallacies in detail.

      Completing this unit should take you approximately 3 hours.

    • Unit 6: Scientific Reasoning

      Unlike the syllogistic arguments you explored in the last unit, which are a form of deductive argument, scientific reasoning is empirical. This means that it depends on observation and evidence, not logical principles. Although some principles of deductive reasoning do apply in science, such as the principle of contradiction, scientific arguments are often inductive, and for this reason, science often deals in confirmation and disconfirmation.

      Nonetheless, there are general guidelines about what constitutes good scientific reasoning, and scientists are trained to be critical of their own inferences as well as those of others in the scientific community. In this unit, you will investigate some standard methods of scientific reasoning, some principles of confirmation and disconfirmation, as well as some techniques for identifying and reasoning about causation.

      Completing this unit should take you approximately 4 hours.

    • Unit 7: Strategic Reasoning and Creativity

      While the majority of this course has focused on the types of reasoning that is necessary to critique and evaluate existing knowledge, or to extend our knowledge in accordance with correct procedures and rules, there remains an enormous branch of our reasoning practice that runs in the opposite direction. Strategic reasoning, problem solving, and creative thinking all rely on an ineffable component of novelty supplied by the thinker.

      Despite the seemingly mystical nature of such activity, problem solving and creative thinking are best approached by following a set of tried and tested procedures, which prompt our cognitive faculties to produce new ideas and solutions by extending our existing knowledge. In this unit, you will investigate techniques for problem solving, representing complex problems visually, making decisions in risky and uncertain scenarios, and creative thinking in general.

      Completing this unit should take you approximately 2 hours.

    • Study Guide

      This study guide will help you get ready for the final exam. It discusses the key topics in each unit, walks through the learning outcomes, and lists important vocabulary terms. It is not meant to replace the course materials!

    • Course Feedback Survey

      Please take a few minutes to give us feedback about this course. We appreciate your feedback, whether you completed the whole course or even just a few resources. Your feedback will help us make our courses better, and we use your feedback each time we make updates to our courses.

      If you come across any urgent problems, email contact@saylor.org or post in our discussion forum.

    • Certificate Final Exam

      Take this exam if you want to earn a free Course Completion Certificate.

      To receive a free Course Completion Certificate, you will need to earn a grade of 70% or higher on this final exam. Your grade for the exam will be calculated as soon as you complete it. If you do not pass the exam on your first try, you can take it again as many times as you want, with a 7-day waiting period between each attempt.

      Once you pass this final exam, you will be awarded a free Course Completion Certificate.

    • Saylor Direct Credit

      Take this exam if you want to earn college credit for this course. This course is eligible for college credit through Saylor Academy's Saylor Direct Credit Program.

      There is a new version of this course as of June 2023.

      The current Saylor Direct Credit Final Exam for this course can be found in the updated version, here: PHIL102: Introduction to Critical Thinking and Logic.

      Please enroll in the new version of the course to access the exam.