Source : Webster's Revised Unabridged Dictionary (1913)

   3. Due exercise of the reasoning faculty; accordance with, or
      that which is accordant with and ratified by, the mind
      rightly exercised; right intellectual judgment; clear and
      fair deductions from true principles; that which is
      dictated or supported by the common sense of mankind;
      right conduct; right; propriety; justice.

            I was promised, on a time, To have reason for my
            rhyme.                                --Spenser.

            But law in a free nation hath been ever public
            reason; the enacted reason of a parliament, which he
            denying to enact, denies to govern us by that which
            ought to be our law; interposing his own private
            reason, which to us is no law.        --Milton.

            The most probable way of bringing France to reason
            would be by the making an attempt on the Spanish
            West Indies.                          --Addison.

   4. (Math.) Ratio; proportion. [Obs.] --Barrow.

   {By reason of}, by means of; on account of; because of.
      ``Spain is thin sown of people, partly by reason of the
      sterility of the soil.'' --Bacon.

   {In reason},

   {In all reason}, in justice; with rational ground; in a right
      view.

            When anything is proved by as good arguments as a
            thing of that kind is capable of, we ought not, in
            reason, to doubt of its existence.    --Tillotson.

   {It is reason}, it is reasonable; it is right. [Obs.]

            Yet it were great reason, that those that have
            children should have greatest care of future times.
                                                  --Bacon.

   Syn: Motive; argument; ground; consideration; principle;
        sake; account; object; purpose; design. See {Motive},
        {Sense}.