Module 1: The Basics of Logical Analysis
Basics of Logical Analysis Overview
Logic is the study of the human activity of reasoning. Like many human activities, reasoning can be done well, or it can be done poorly. The goal of logic is to distinguish good reasoning from bad. Good reasoning is not necessarily effective reasoning; in fact, as we shall see, bad reasoning is pervasive and often extremely effective—in the sense that people are often persuaded by it. In Logic, the standard of goodness is not about effective persuasiveness, but rather correctness according to logical rules.
Our goal in the study of logic is to distinguish good reasoning from faulty reasoning. We study rules and techniques that allow us to make this distinction. Logic describes good (or correct) reasoning – how we should reason. It is important to note that this approach sets logic apart from at least one alternative way of studying human reasoning, one proper to the discipline of psychology. Here it is possible to study human reasoning in a merely descriptive mode: to identify common patterns of reasoning and, for example, to explore their psychological causes. But that is not logic. Logic takes up reasoning in a prescriptive mode: it tells how we ought to reason, not merely how we in fact typically do.
As an example, psychologists have determined that most people are subject to what is called “confirmation bias”—a tendency to seek out information to confirm one’s pre-existing beliefs and ignore contradictory evidence. There are lots of studies on this effect, even including brain scans of people engaged in evaluating evidence. All of this is very interesting, but it’s psychology, not logic; it’s a mere descriptive study of reasoning. In the study of how we should reason, logic can help us recognize that some common reasoning patterns are faulty reasoning.
Learning Objectives
After successful completion of Module 1, you will be able to:
- Describe the components and basic structure of arguments.
- Identify the parts of simple ordinary-language arguments, distinguishing a conclusion from supporting premises.
- Distinguish between arguments and explanations.
- Recognize essential features of deduction, induction, validity, soundness, and strength.
Module 1 Roadmap
- Section 1.1: We begin by gaining an understanding of the basic building blocks of logic: propositions and arguments.
- Section 1.2: Then we work on recognizing arguments in natural language and identifying the claim (or conclusion0 that the arguer is attempting to prove.
- Section 1.3: We finish the module with an introduction to the two basic types of reasoning — deduction and induction.
Key Terms
- argument
- conclusion
- counterexample
- deductive argument
- enthymeme
- explicate (an argument)
- indicator words
- inductive argument
- inference
- invalidity
- logic
- premise
- proposition
- soundness
- strong
- tacit
- validity
- weakness
Definitions for these terms are available in the Glossary.
Candela Citations
- Retrieved from: https://open.umn.edu/opentextbooks/textbooks/fundamental-methods-of-logic. License: CC BY: Attribution
