There are three fundamental Laws of Logic:

  1. The law of identity: P is P or Something is what it is.
  2. The law of noncontradiction: P is not non-P or Something is something else.
  3. The law of excluded middle: Either P or non-P or Something is or something isn’t.

Examples:

The law of identity: If it’s raining outside, it’s raining outside.

The law of noncontradiction: If it’s raining outside, it’s not not raining outside.

The law of excluded middle: If it’s raining outside, that statement is either true of false, there is

no alternative.