The Fundamental Laws and Principles of Logic --Introduction

This entry describes the four fundamental laws of logic, and introduces the basic logical forms.

The four fundamental laws of logic (also called the first-principles of epistemology) are:
(1) the law of non-contradiction,
(2) the law of the excluded middle,
(3) the law of identity, and
(4) the law of rational inference.

In addition to the above four laws, there are two fundamental logical
forms, or principles: that of of affirmation and that of denial.