“Tell me,” you say, “if you do not know whether a man is grateful or ungrateful, will you wait until you do know, or will you refuse to lose the opportunity of giving a benefit? To wait is a long matter, — for, as Plato says, the human heart is hard to divine, — not to wait hazardous.” Our answer to this will be that we never wait for absolute certainty, since the discovery of truth is difficult, but follow the path that probable truth shows. All the business of life proceeds in this way. It is thus that we sow, that we sail the sea, that we serve in the army, that we take wives, that we rear children; since in all these actions the issue is uncertain, we follow the course that we believe offers the hope of success. For who will promise to the sower a harvest, to the sailor a port, to the soldier a victory, to a husband a chaste wife, to a father dutiful children? We follow, not where truth, but where reason, directs us. If you wait to do only what is assured of success and to have only the knowledge that comes from ascertained truth, all activity is given up, and life comes to a halt. Since it is, not truth, but the probable truth, that impels me in one direction or another, I shall give my benefit to the man who in all probability will be grateful.