Philo Judaeus De Fuga Et Inventione 118

[118] For if while the word remained and was healthy in us, error was driven to a distance, by all means, when the word departs, error will be introduced. For the undefiled high priest, conscience, has derived from nature this most especial honour, that no error of the mind can find any place within him; on which account it is worth our while to pray that the high priest may live in the soul, being at the same time both a judge and a convictor, who having received jurisdiction over the whole of our minds, is not altered in his appearance or purpose by any of those things which are brought under his judgment.