And th e best, the ."liveliest of all objects" that can wake us as if from a dr ea m and give us v igor is "a rational and t hinking Be ing like ourselves" who comm unicates to us all the actions of his mind ; makes us pri vy to his inmost sentiments an d affections; and lets us see, in the very instant of their production, all the emotions, which are caus'd by any object. Every lively idea is agreeable, but especia ll y that of a passion, because such an idea becomes a kind of pas sion, and gives a more sensible agitation to the mind, than any oth er image or conception. (T, 353) Thi s id eal, th e per son to whose "inmos t sentiments and affectio ns " we are pr i vy- total kn owledge of a nother 's emotions- is on e that m ay be hard to attain in real lif e. In the Tr eatise, Hu me seems rel atively un- concerne d with th e qu es ti on of how we really know what other p eo- ple's feelings truly are, a problem Adam Smith makes cen tral to his ac- co unt of sympa th y in A Theo ry of Mo ral Senthnent