Kantian enthusiasm

This perfect concept of a thing is the idea, and if one imagines an image complying to this idea, it's an ideal. Because this idea is model for perfection, it is going to suit us so much that we will tend to believe that is can really exist in this world. Thus, all of us have in mind an idea of all-pure friendship, even though it doesn't exist anywhere in the whole world. You can judge any friendship by the light of this idea. But he who achieves it, who expect it to happen in the real world, and as intensively as he imagines it in his mind, this one knows friendship enthusiasm. On the same note, there is patriotism enthusiasm, where one creates an ideal of perfect union among civil society and for the good of it all; when, with affect, ones adopt this ideal, which however cannot be reached, he is an enthusiast. Such enthusiasm leads to great excess, so much that the person keen on this idea will sacrifice friendship, natural bonds, and all the rest.

Then, if the ideal cannot be reached, this kind of enthusiasm makes misanthropes. The misanthrope runs away from men not from bad intention because he can't stand them, but because he cannot find anywhere persons such as he would like, grateful persons, benevolent to all mankind. He is a whimsical righteous person, pursuing his ideal with affect. This ideal can undoubtedly be used as a rule and as a benchmark but it cannot be really achieved. Such enthusiasts are not mean persons, on the contrary, they are full of benevolent principles towards the human species, and as they cannot find anything similar, become misanthropes, for example Rousseau, and people judge them mad for having such principles exposing themselves to other's judgement.

Kant - On men's state in slumber or in dream