On the Sacrifice of Abel and Cain (34-36)

Now, on account of these things, and because of what was said before, namely, that the things which are really pious, holy, and good do naturally utter a voice from themselves, even while they keep silence, I will desist from saying any more about them; for neither does the sun nor the moon require an interpreter, because they, being on high, fill the whole world with light, the one shining by day and the other by night. But their own brilliancy is an evidence in their case which stands in no need of witnesses, but which is confirmed by the eyes, which are more undeniable judges than the ears.

But I will speak with all freedom of that point in virtue which appears to have the greatest amount of difficulty and perplexity, for this, too, does appear to the imagination, at their first meeting, to be troublesome; but, on consideration, it is found to be very pleasant and, as arising from reason, to be suitable. But labour is the enemy of laziness, as it is in reality the first and greatest of good things, and wages an irreconcileable war against pleasure; for, if we must declare the truth, God has made labour the foundation of all good and of all virtue to man, and without labour you will not find a single good thing in existence among the race of men.

For, as it is impossible to see without light, since neither colours nor eyes are sufficient for the comprehension of things which we arrive at by means of sight (for nature has made light beforehand to serve as a link to connect the two, by which the eye is brought near and adapted to colour, for the powers of both eye and of colour are equally useless in darkness), so in the same manner is the eye of the soul unable to comprehend anything whatever of the actions in accordance with virtue, unless it takes to itself labour as a coadjutor, as the eye borrows the assistance of light; for this, being placed in the middle, between the intellect and the good object which the intellect desires, and understanding the whole nature of both the one and the other, does itself