On the Creation of the World (153-154)

But while man was still living a solitary life, and before woman was created, the history relates that a paradise was planted by God in no respect resembling the parks which are seen among men now. For parks of our day are only lifeless woods, full of all kinds of trees, some evergreen with a view to the undisturbed delectation of the sight; others budding and germinating in the spring season, and producing fruit, some eatable by men, and sufficient, not only for the necessary support of nature as food, but also for the superfluous enjoyment of luxurious life; and some not eatable by men, but of necessity bestowed upon the beasts. But in the paradise, made by God, all the plants were endowed in the souls and reason, producing for their fruit the different virtues, and, moreover, imperishable wisdom and prudence, by which honourable and dishonourable things are distinguished from one

And these statements appear to me to be dictated by a philosophy which is symbolical rather than strictly accurate. For no trees of life or of knowledge have ever at any previous time appeared upon the earth, nor is it likely that any will appear hereafter. But I rather conceive that Moses was speaking in an allegorical spirit, intending by his paradise to intimate the dominant character of the soul, which is full of innumerable opinions as this figurative paradise was of trees. And by the tree of life he was shadowing out the greatest of the virtues—namely, piety towards the gods, by means of which the soul is made immortal; and by the tree which had the knowledge of good and evil, he was intimating that wisdom and moderation, by means of which things, contrary in their nature to one another, are distinguished.