Full Idea
The clearest idea of active power comes to us from the mind. So active power occurs only in things which are analogous to minds, that is, in entelechies; for strictly matter exhibits only passive power.
Clarification
'Entelechies' are actualised essences
Gist of Idea
We discern active power from our minds, so mind must be involved in all active powers
Source
Gottfried Leibniz (New Essays on Human Understanding [1704], 2.21)
Book Reference
Leibniz,Gottfried: 'New Essays on Human Understanding', ed/tr. Remnant/Bennett [CUP 1996], p.172
A Reaction
If this is meant to be a precise argument, then 'so' and 'only' are blatantly unjustified. I guess that if it isn't analogous to a mind then he won't allow it to be a TRUE active power! I say mind arises from the entelechies of the physical brain.