Question

Please explain what deductive logic is. In discussing deductive logic, explain the two levels of evaluation that are used. Please provide an example of a deductive argument.

Answer 1

Deductive logic refers to the process of reasoning from one or more statements or premises to reach a logically certain conclusion. Through deductive logic, it is claimed that if the premises are true it is impossible for the conclusion to be false. Deductive arguments are evaluated using the following parameters:

• Valid versus invalid argument: A valid argument is one where the conclusion follows necessarily from the premises. An invalid argument is one where the conclusion does not follow necessarily from the premises is an invalid argument.
• Sound versus unsound argument: A sound argument is one in which a deductive argument is valid, and when truth value analysis of the premises show that they are all true. If a deductive argument is invalid, or if at least one of the premises is false (truth value analysis), then the argument is unsound.

Example of a deductive argument:

All men are mortal. Socrates is a man. Therefore Socrates is mortal.