The First Principles of Logic:

A Claim For A True Worldview

 The First Principles of Logic:

  1. Identity.
  2. Excluded middle
  3. Sufficient reason.
  4. Contradiction.

There are four first principles of logic (or of human reason); the one we are most concerned with here is the principle of contradiction. To put it in its proper context, however, let us first review the three other first principles of logic.

THE PRINCIPLE OF IDENTITY

Stated: A thing is what it is.

Explanation: The whole of existing reality is not a homogenous mass. It is a composition of individuals, and the individuals are distinguishable from one another.

THE PRINCIPLE OF THE EXCLUDED MIDDLE

Stated: Between being and non-being there is no middle state.

Explanation: Something either exists or it does not exist; there is no halfway point between the two. The lamp sitting on my desk is either really there or it is not. There is no other possibility. We might ask: How about becoming? Isn’t the state of becoming between those of being and non-being? The answer is no. There is no such thing as just becoming; there are only things that become. The state of becoming is already within the realm of existence.

THE PRINCIPLE OF SUFFICIENT REASON

Stated: There is a sufficient reason for everything.

Explanation: The principle could also be called “the principle of causality.” It states that everything that actually exists in the physical universe has an explanation for its existence. What is implied in principle is that nothing in the physical universe is self-explanatory or the cause of itself. (For a thing to be a cause of itself, it would somehow have to precede itself, which is absurd.) One

THE PRINCIPLE OF CONTRADICTION

Stated: It is impossible for something both to be and not be at the same time and in the same respect.

Explanation: This principle could be regarded as a fuller expression of the principle of identity, for if X is X (principle of identity) it cannot at one and the same time be non-X (principle of contradiction). ………………………….

Source: McInerny, D.Q.. Being Logical: A Guide to Good Thinking. Kindle Edition.