This way of talking causes confusion of thought.
This way of talking, nevertheless, has prevailed, and, as I guess, produced great confusion.

For these being all different powers in the mind, or in the man, to do several actions, he exerts them as he thinks fit: but the power to do one action is not operated on by the power of doing another action.

For the power of thinking operates not on the power of choosing, nor the power of choosing on the power of thinking; no more than the power of dancing operates on the power of singing, or the power of singing on the power of dancing, as any one who reflects on it will easily perceive.

And yet this is it which we say when we thus speak, that the will operates on the understanding, or the understanding on the will.
19.

Powers are relations, not agents.
I grant, that this or that actual thought may be the occasion of volition, or exercising the power a man has to choose; or the actual choice of the mind, the cause of actual thinking on this or that thing: as the actual singing of such a tune may be the cause of dancing such a dance, and the actual dancing of such a dance the occasion of singing such a tune.