De Plantatione

We must therefore have recourse to allegory, which is a favourite with men capable of seeing through it; for the sacred oracles most evidently conduct us towards and instigate us to the pursuit of it. For they say that in the Paradise there were plants in no respect similar to those which exist among us; but they speak of trees of life, trees of immortality, trees of knowledge, of comprehension, of understanding; trees of the knowledge of good and evil.