The Structure of Arguments

Whenever people offer reasons or evidence for the truth of a statement, they are advancing an argument.

In this part of our logic course, we investigate some of the ways that logical inferences can be evaluated.

In sum, logic is a study of sorting valid or reliable arguments from invalid or unreliable ones in accordance with specific rules.

From a logical point of view, the expression of strong feeling is termed emotive discourse, not argumentative discourse. So the definition of “argument” in this course is considerably narrower than its lexical definition indicates.

Most of ordinary discourse is not argumentative.

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  Philosophy and Logic

  The subjects of philosophy and logic are broadly characterized.

• The Nature of Logic

  Some of the uses of logic are illustrated, and deductive arguments are briefly distinguished from inductive arguments.

• The Structure of Arguments

  The concept of an argument is discussed together with the related concepts of premise, conclusion, inference, entailment, proposition, and statement.

• Diagramming Arguments

  The representation of the structure of arguments by means of diagrams is explained and illustrated with examples.

• Explanations and Nonarguments

  Several kinds of nonargumentative discourse are characterized, illustrated, and distinguished from argumentative discourse.

• Deduction and Induction

  Deductive and inductive arguments are characterized and distinguished in some detail.

• Truth, Validity, and Soundness

  The foundation-concepts of deductive logic are explained — truth, validity, and soundness.