Improper reductions implicitly presuppose the prior facticity of the whole that their explanations presume to explain is wholly generated by or epiphenomenal to its parts – is “nothing but” those parts. They employ the whole as an explanatory factor of the whole. So they are circular. “The cells of the animal signal to each other thusly, and so there is an animal.” Would there be such cells in the first place, or their signals, or indeed their own constituent parts together with their intracellular signals, if there were not already an animal, of which they were constituent parts? No. There would be no cells, no signals. The entire panoply of explanatory entities then would be eliminated. You can’t obtain even a quantum of action in the life of an animal if there are no such things as animal lives, but only quanta of action.