IMPLICATION

Two men worked on a large ocean-going vessel. One day the mate, who normally did not drink, became intoxicated. The captain, who hated him, entered in the daily log: "Mate drunk today." He knew this was his first offense, but he wanted to get him fired. The mate was aware of his evil intent and begged him to change the record. The captain, however, replied, "It's a fact, and into the log it goes!" A few days later the mate was keeping the log, and concluded it with: "Captain sober today." Realizing the implication of this statement, the captain asked that it be removed. In reply the mate said,  "It's a fact, and in the log it stays!"

Source Unknown.