[38] wherefore Plato has well said: [18]—"For nothing ever departed from it, nor did anything ever come to it from any quarter; for that was not possible; for there was nothing in existence which could come; for since it supplies itself with nutriment out of its own consumption, it also does everything and suffers everything in itself and by itself, and is compounded with the most consummate art. For he who created it thought that it would be better if wholly self-sufficient, than if in continual need of accessories from other quarters."