Logical Strength Logical strength

A measure of the likelihood that the conclusion of an argument is true given that its premises are all true. The easiest way to determine the logical strength of an argument is to ask what the likelihood is of the conclusion's being false assuming that the premises are all true. For example, the argument,

All men are mortal.

Socrates is a man.

Therefore, Socrates is mortal


has a very high degree of logical strength because the likelihood that the conclusion is false given that the premises are all true is nil. By comparison, the argument,

Hardly any men are honest.

Socrates is a man.

Therefore, Socrates is honest.


has a low degree of logical strength because the likelihood that the conclusion is false given that the premises are all true is high.