What is the logical form of an argument?

The logical form of an argument is composed from the logical forms of its component statements or sentences. These logical forms are especially helpful for assessing the validity of deductive arguments.

How do you identify the logical forms of a statements?

A statement form (or propositional form, or logical form) is an expression made up of statement variables, called compo- nent statements, (such as p, q, and r), and logical connectives (such as ∼, ∨ and ∧) that becomes a statement when actual statements are substituted for the component statement variables.

What is standard logical form?

The standard form of an argument is a way of presenting the argument which makes clear which statements are premises, how many premises there are, and which statements is the conclusion. In standard form, the conclusion of the argument is listed last.

What is an if then argument?

If–then arguments , also known as conditional arguments or hypothetical syllogisms, are the workhorses of deductive logic. They make up a loosely defined family of deductive arguments that have an if–then statement —that is, a conditional—as a premise. The conditional has the standard form If P then Q.

What is an example of logical form?

Thus, for example, the expression “all A’s are B’s” shows the logical form which is common to the sentences “all men are mortals,” “all cats are carnivores,” “all Greeks are philosophers,” and so on.

What is an example of a logical argument?

Example. The argument “All cats are mammals and a tiger is a cat, so a tiger is a mammal” is a valid deductive argument. Both the premises are true. To see that the premises must logically lead to the conclusion, one approach would be use a Venn diagram.

What is conditional argument?

A conditional argument composed of categorical statements is readily judged to be either valid or invalid; validity is not a matter of degree, and the truth of the conclusion of a valid argument is guaranteed by the truth of its premises.

What are forms of conditional arguments?

Conditional statements take several forms including the converse, inverse, contrapositive, and necessary which take the following forms:

  • Converse: If q, then p.
  • Inverse: If not p, then not q.
  • Contrapositive: If not q, then not p.
  • Necessary: If, and only if, p, then q.

What is a conditional statement in an argument?

A conditional asserts that if its antecedent is true, its consequent is also true; any conditional with a true antecedent and a false consequent must be false. For any other combination of true and false antecedents and consequents, the conditional statement is true.

What is a valid argument and how is it different from a sound argument?

An argument form is valid if and only if whenever the premises are all true, then conclusion is true. An argument is valid if its argument form is valid. For a sound argument, An argument is sound if and only if it is valid and all its premises are true.

What is an example of a conditional statement?

Example. Conditional Statement: “If today is Wednesday, then yesterday was Tuesday.” Hypothesis: “If today is Wednesday” so our conclusion must follow “Then yesterday was Tuesday.” So the converse is found by rearranging the hypothesis and conclusion, as Math Planet accurately states.

What is the logical form of denying the consequent?

(also known as: inverse error, inverse fallacy) Description: It is a fallacy in formal logic where in a standard if/then premise, the antecedent (what comes after the “if”) is made not true, then it is concluded that the consequent (what comes after the “then”) is not true.

What is a valid argument?

An argument is valid if the premises and conclusion are related to each other in the right way so that if the premises were true, then the conclusion would have to be true as well.

Is denying the consequent valid or invalid?

The opposite statement, denying the consequent, is a valid form of argument. Denying the consequent can be considered a form of abductive reasoning.

Why is denying the consequent valid?

Like modus ponens, modus tollens is a valid argument form because the truth of the premises guarantees the truth of the conclusion; however, like affirming the consequent, denying the antecedent is an invalid argument form because the truth of the premises does not guarantee the truth of the conclusion.

Is affirming the consequent a valid argument form?

Affirming the consequent is a valid argument form. An argument of this form—If p, then q; p; therefore, q—is called modus ponens. An argument of this form—If p, then q; not p; therefore, not q—is called modus tollens. This argument form known as modus tollens is valid.

What are logical fallacies in an argument?

Logical fallacies are arguments that may sound convincing, but are based on faulty logic and are therefore invalid. They may result from innocent errors in reasoning, or be used deliberately to mislead others. Taking logical fallacies at face value can lead you to make poor decisions based on unsound arguments.

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