sdi

A very short, but very difficult tractate: not because the concepts themselves are difficult, but because the ramifications of them are sprawling, complex, and many-faceted.

II 6: Quality and Form-Idea
A quality is something that is not essential to a thing. For example, paper may have the quality of being "colorful," because if lost its color, it would still be paper; but a rainbow cannot be said to have the quality of being "colorful," because if it weren't colorful, it wouldn't be a rainbow.
Qualities, therefore, may only exist where there is the potential for the quality to exist, and they are therefore limited to the lower worlds. We might say of fire that it is warm, it is bright, it is destructive, etc., and of a material fire that may be so. But let us consider ideal Fire: it has no potential, only actuality; it does not have qualities, it acts. Rather than being warm, it warms; rather than being bright, it brightens; rather than being destructive, it destroys; etc.
The lower worlds aren't Real because they have a qualified existence; Reality is that which exists of itself.

Our souls reside, of course, in the empyrean, and so one wonders what one's own Real form is when all quality is stripped away.