# Is there a category of categories?

My question is quite simple, I would like to know if we can define the category of the categories, unlike Cat which is the category of the small categories. By the way, are there any particular reason why we define Cat in this way?

• There is no category of categories, because of size issues. See [this answer][1]. [1]: math.stackexchange.com/a/717993/2614 Apr 12, 2014 at 15:05
• @BrunoStonek I don't think the answer gives the question enough credit, since there is a thing called $\mathbf{CAT}$, which some people even call a category. My knowledge about this stuff is not sufficiant enough to give a good answer, though.... Apr 15, 2014 at 8:07
• @roman: true enough. I remember "The joy of cats" calling it a "quasicategory", although I don't think I even read how they defined that concept. Apr 15, 2014 at 8:13