 fail to notice that the mind needs only discernment and accuracy in all its actions, and that anyone who displays these qualities in one context is capable of applying them as easily and in the same way to everything else. Morality and social science do not change the nature of our actions; the latter always remain physical, […] Once someone understands the laws of motion in natural philosophy, they can apply them to all changes and all variations that occur in nature. Similarly, if someone has once understood the true principles of the social sciences, they do not experience a new challenge when applying them to novel situations that occur. (T1en 174; TTfr 116–117)