The desire to smash comes from the lower centers.

We can quite well recognize the will exerted from the lower center. We call it headstrong temper and masterfulness. But the peculiar will of the upper center — the sort of nervous, critical objectivity, the deliberate forcing of sympathy, the play upon pity and tenderness, the plaintive bullying of love, or the benevolent bullying of love — these we don’t care to recognize. They are the extravagance of spiritual will. But in its true harmony the thoracic ganglion is a center of happier activity: of real, eager curiosity, of the delightful desire to pick things to pieces, and the desire to put them together again, the desire to “find out,” and the desire to invent: all this arises on the upper plane, at the volitional center of the thoracic ganglion.