A Priori (Logic)/Examples

Examples of Use of A Priori

Probability

The following is an example of a priori reasoning:

The probability of rolling a $6$ on a fair die is $\dfrac 1 6$.

The truth of the above statement is dependent upon:

the definition of the term probability

the definition of a fair die.

A Legal Statement

The following is an example of a priori reasoning:

If Fred Bloggs has committed a crime, then he is guilty.

The truth of the above statement is dependent upon the definition of the term guilty, which, in natural language simply means having committed a crime.

Contrast this with:

Fred Bloggs has committed the crime of usury

the truth value of which is dependent upon knowing whether or not he actually did it.