# Argument form

 related topics {theory, work, human} {language, word, form} {math, number, function}

In logic, the argument form or test form of an argument results from replacing the different words, or sentences, that make up the argument with letters, along the lines of algebra; the letters represent logical variables. This is of importance since the validity of an argument is determined solely by its form. The sentence forms which classify argument forms of common important arguments are studied in logic.

## Contents

### Example

To demonstrate the important notion of the form of an argument, substitute letters for similar items throughout the sentences in the original argument.

All we have done in the Argument form is to put 'S' for 'human' and 'humans', 'P' for 'mortal', and 'a' for 'Socrates'; what results, is the form of the original argument. Moreover, each individual sentence of the Argument form is the sentence form of its respective sentence in the original argument.[1]

### Importance

Attention is given to argument and sentence form, because form is what makes an argument valid or cogent. Some examples of valid argument forms are modus ponens, modus tollens, disjunctive syllogism, hypothetical syllogism and dilemma. Two invalid argument forms are affirming the consequent and denying the antecedent.