If you want to know something else about beauty, what precisely it is, look at a history of art. You will see that every age has had its ideal Venus (or Apollo), and that all of these Venuses and Apollos put together and compared out of the context of their periods are nothing less than a family of monsters.— Bruno Munari
A thing is not beautiful because it is beautiful, as the he-frog said to the she-frog, but because one likes it.
I’m not ready to agree that this is true, since while fashion changes across history, what is considered beautiful has turned out to be not quite as arbitrary or mutable as is suggested here. The observation that many things are relative has merit, but in strictest construction, it is not necessary to bite this post-modern bullet.