134. Let not thy warning be harsh, nor thy rebuke bitter, Cic. de Off. I. 38, § 137. for as friendship ought to avoid flattery, so, too, ought it to be free from arrogance. For what is a friend but a partner in love, Cic. de Amic. 21, § 80. to whom thou unitest and attachest thy soul, and with whom thou blendest so as to desire from being two to become one; to whom thou entrustest thyself as to a second self, from whom thou fearest nothing, and from whom thou demandest nothing dishonourable for the sake of thine own advantage. Friendship is not meant as a source of revenue, Cic. de Amic. 15, § 51. but is full of seemliness, full of grace. Friendship is a virtue, not a way of making money. It is produced, not by money, but by esteem; not by the offer of rewards, but by a mutual rivalry in doing kindnesses.