And “envy” too is caused by lacking the blessing that would make the envier equal or superior to the person envied. This makes the envier resent the envied person’s being his equal or superior. Likewise, wickedness—such as killing, illicit sexual intercourse, and all other vile deeds—is caused only by the soul’s need to find satisfaction through killing or pleasure through illicit intercourse. Otherwise, someone who achieves his aim without killing or obtains pleasure without illicit intercourse does not commit such acts. Need, in turn, originates in nonexistence.

If one reflects on this, it becomes clear that when existing evil is attributed to either nonexistence or existence, it must be deficient existence. Sometimes it is attributed to a lack of completeness in the cause or the absence of a condition; at other times, it is attributed to something existent. It is also sometimes described in terms of a deficient cause and a deficient subject. This deficiency is caused either by the absence of a condition or by the presence of an obstacle. An obstacle can only obstruct because the impelling cause is weak.

Everything I have mentioned is clear and evident except this point, which contains an obscurity that reflection will dispel. It has two aspects:

“First,” something existent cannot have sheer nonexistence as its cause.

“Second,” something existent cannot be a cause of sheer nonexistence. This is self-evident: existing things proceed only from something real and existent.