Enneads I.8: Of the Nature and Origin of Evils
Weakness of the Soul as an Explanation of Evil
14. Wickedness is by some explained as weakness of the soul, because the wicked soul is impressionable, mobile, easy to lead to evil, disposed to listen to her passions, and equally likely to become angry, and to be reconciled; she yields inconsiderately to vain ideas, like the weakest works of art and of nature, which are easily destroyed by winds and storms. This theory (is attractive, but implies a totally new conception, that of “weakness” of soul, and it would have) to explain this “weakness,” and whence it is derived; for weakness in a soul is very different from weakness in a body, but just as in the body weakness consists in inability to fulfil a function, in being too impressionable, the same fault in the soul might, by analogy, be called by the same name, unless matter be equally the cause of both weaknesses. Reason, however, will have to explore the problem further, and seek the cause of the soul-fault here called weakness.
WEAKNESS OF THE SOUL OCCURS CHIEFLY IN SOULS FALLEN INTO MATTER.
In the soul weakness does not derive from an excess of density or rarefaction of leanness or stoutness, nor of any sickness such as fever. It must be met in souls which are either entirely separated from matter, or in those joined to matter, or in both simultaneously. Now, as it does not occur in souls separated from matter, which are entirely pure, and “winged,” and which, as perfect, carry out their functions without any obstacle; it remains, that this weakness occurs in fallen souls, which are neither pure nor purified. For them weakness consists not in the privation of anything, but in the presence of something alien, just as, for instance, weakness of the body consists in the presence of slime or bile. We shall, therefore, be able to understand clearly the weakness of the soul by ferreting out the cause of the “fall” of the soul.