And it's good reason for them to be obsessed with the idea of universals, because all of science, through the 19th century and much of the 20th, was obsessed with universals.
他们沉迷于共性是有原因的， 因为所有科学领域，在整个19世纪和20世纪的绝大部分里， 都沉迷于共性。