But observe that energy and capacity for energy, and the product of energy, and the agent of energy, are all different. Energy is the efficient (δραστική) and essential activity of nature: the capacity for energy is the nature from which proceeds energy: the product of energy is that which is effected by energy: and the agent of energy is the person or subsistence which uses the energy. Further, sometimes energy is used in the sense of the product of energy, and the product of energy in that of energy, just as the terms creation and creature are sometimes transposed. For we say “all creation,” meaning creatures.