In any case, you can't have effective allegory in times when people are swept this way and that by momentary convictions, because everyone will read it differently. You can't indicate moral values when morality changes with what is being done, because there is no accepted basis of judgment. And you cannot show the operation of grace when grace is cut off from nature or when the very possibility of grace is denied, because no one will have the least idea of what you are about.
In order to get over the ethical difficulties presented by the naive naturalism of many parts of those Scriptures, in the divine authority of which he firmly believed, Philo borrowed from the Stoics (who had been in like straits in respect of Greek mythology), that great Excalibur which they had forged with infinite pains and skill—the method of allegorical interpretation. This mighty 'two-handed engine at the door' of the theologian is warranted to make a speedy end of any and every moral or intellectual difficulty, by showing that, taken allegorically or, as it is otherwise said, 'poetically' or, 'in a spiritual sense,' the plainest words mean whatever a pious interpreter desires they should mean.