Calculations have merely practical, not theoretical, value. It may even be said that where calculation begins, comprehension ceases; for a brain occupied with numbers is, as long as it calculates, entirely estranged from the causal connection in physical processes, being engrossed in purely abstract, numerical conceptions. The result, however, only shows us how much, never what. "L'experience et le calcul," those watchwords of French physicists, are not therefore by any means adequate [for thorough insight].)— If, again, stimuli are the guides of the Understanding, it will produce Physiology of Plants and Animals, Therapeutics, and Toxicology. Finally, if it devotes itself to the study of motives, the Understanding will use them, on the one hand, theoretically, to guide it in producing works on Morality, Jurisprudence, History, Politics, and even Dramatic and Epic Poetry; on the other hand, practically, either merely to train animals, or for the higher purpose of making human beings dance to its music, when once it has succeeded in discovering which particular wire has to be pulled in order to move each puppet at its pleasure. Now, with reference to the function which effects this, it is quite immaterial whether the intellect turns gravitation ingeniously to account, and makes it serve its purpose by stepping in just at the right time, or whether it brings the collective or the individual propensities of men into play for its own ends. In its practical application we call the Understanding shrewdness or, when used to outwit others, cunning ; when its aims are very insignificant, it is called slyness and, if combined with injury to others, craftiness. In its purely theoretical application, we call it simply Understanding, the higher degrees of which are named acumen, sagacity, discernment, penetration, while its lower degrees are termed dulness, stupidity, silliness, &c. &c. These widely differing degrees of sharpness are innate, and cannot be acquired ; although, as I have already shown,
