without experiencing fatigue. Consider, for example, a magnet holding a piece of iron suspended for a time: it does not tire, its attractive force does not weaken, and the attachment does not cease unless some new external factor intervenes. Rather, movement dissipates the substance of the spirit within us—that is, within our limbs—because they are composed of subtle and dense elements.

The subtle element is susceptible to dissolution, and movement brings this about. When the spirit to which the motive power is attached dissipates, the motive power within us weakens and becomes incapable of acting in our limbs through fatigue and weariness.

This is absent from heaven only because composition and dissolution are absent from it, not because of whether or not nature there opposes will. Such opposition is a remote cause of fatigue and weariness; the immediate cause is what we have described.

If it is absent from heaven for this reason, is it not all the more fitting that it should be absent from the heaven of heaven, the simplest of simples, one in essence?

He said:

“As for his statement, ‘Not seeing some things is better than seeing them,’ this is the most plausible of the arguments he has offered, and the most likely to gain currency and acceptance before careful consideration. Yet this holds only in relation to us, given our limited capacity and time.

“Thus, it is valid to say that occupying ourselves with seeing what is superior is preferable to occupying ourselves with what is inferior. But if