Philo called the rule that a judge should not receive the testimony of a single witness "an excellent commandment." Philo argued first that a person might inadvertently gain a false impression of a thing or be careless about observing and therefore be deceived. Secondly, Philo argued it unjust to trust to one witness against many persons, or indeed against only one individual, for why should the judge trust a single witness testifying against another, rather than the defendant pleading on the defendant's own behalf? Where there is no preponderance of opinion for guilt, Philo argued, it is best to suspend judgment.