Principle of Non-Contradiction. A statement and its negation cannot both
Example a: It is raining—It is not raining. With no
further qualification, only ONE of these statements can be true.
Example b: All men are mortals
— Not all men are mortals.
Principle of Identity. A statement's contention asserts fully and
only that contention.
Example a: It is raining. This means and
ONLY means that it
3. Principle of Excluded Middle. The statement or its
negation must be true.
a: It is raining—It is not raining. With no
further qualification, one of them MUST be true.
4. Principle of Sufficient Reason. Whether a statement,
information, or a
course of thinking is valid depends upon whether it is more
reasonable to accept than not to accept.
The author of this site
is dedicated to being circumspect
and honorable in his presentation of material and his arguments
for support of positions, and pledges to be consistent with
the valid principles of thought. This is just being intellectually