Philo Judaeus De Sacrificiis Abelis Et Caini 37

For, choose whatever good thing you please, and you will find that it owes its existence and all its strength and solidity to labour. Now, piety and holiness are good things, but still we are not able to attain to them without the worship of the gods, and the worship of them is combined with perseverance in labours. Again, prudence and courage and justice are all beautiful things and perfect goods, but still they are not to be acquired by laziness, and we must be content if they can be attained to by continued diligence. Now, since the organs of every soul are not able to support a familiarity with God and with virtue, as being a very intense and mighty harmony, they very often get lax and become remiss so as to descend from the highest unto those of more moderate character;