Source : Webster's Revised Unabridged Dictionary (1913)

      The soul of man is an active principle.     --Tillotson.

   3. An original faculty or endowment.

            Nature in your principles hath set [benignity].
                                                  --Chaucer.

            Those active principles whose direct and ultimate
            object is the communication either of enjoyment or
            suffering.                            --Stewart.

   4. A fundamental truth; a comprehensive law or doctrine, from
      which others are derived, or on which others are founded;
      a general truth; an elementary proposition; a maxim; an
      axiom; a postulate.

            Therefore, leaving the principles of the doctrine of
            Christ, let us go on unto perfection. --Heb. vi. 1.

            A good principle, not rightly understood, may prove
            as hurtful as a bad.                  --Milton.

   5. A settled rule of action; a governing law of conduct; an
      opinion or belief which exercises a directing influence on
      the life and behavior; a rule (usually, a right rule) of
      conduct consistently directing one's actions; as, a person
      of no principle.

            All kinds of dishonesty destroy our pretenses to an
            honest principle of mind.             --Law.

   6. (Chem.) Any original inherent constituent which
      characterizes a substance, or gives it its essential
      properties, and which can usually be separated by
      analysis; -- applied especially to drugs, plant extracts,
      etc.

            Cathartine is the bitter, purgative principle of
            senna.                                --Gregory.

   {Bitter principle}, {Principle of contradiction}, etc. See
      under {Bitter}, {Contradiction}, etc.

Contradiction \Con`tra*dic"tion\, n. [L. contradictio answer,
   objection: cf. F. contradiction.]
   1. An assertion of the contrary to what has been said or
      affirmed; denial of the truth of a statement or assertion;
      contrary declaration; gainsaying.

            His fair demands Shall be accomplished without
            contradiction.                        --Shak.

   2. Direct opposition or repugnancy; inconsistency;
      incongruity or contrariety; one who, or that which, is
      inconsistent.

            can be make deathless death? That were to make
            Strange contradiction.                --Milton.

            We state our experience and then we come to a manly
            resolution of acting in contradiction to it.
                                                  --Burke.

            Both parts of a contradiction can not possibly be
            true.                                 --Hobbes.

            Of contradictions infinite the slave. --Wordsworth.

   {Principle of contradiction} (Logic), the axiom or law of
      thought that a thing cannot be and not be at the same
      time, or a thing must either be or not be, or the same
      attribute can not at the same time be affirmed and and
      denied of the same subject.

   Note: It develops itself in three specific forms which have
         been called the ``Three Logical Axioms.'' First, ``A is
         A.'' Second, ``A is not Not-A'' Third, ``Everything is
         either A or Not-A.''