This a topic that also comes up in linear algebra. Is there any analogy between ...

catnaroek · on July 23, 2017

It's not a coincidence. The terms “covariance” and “contravariance” ultimately come from category theory.

jacobolus · on July 24, 2017

According to Wikipedia:

> The terms "covariant" and "contravariant" were introduced by James Joseph Sylvester in 1853 in the context of algebraic invariant theory, where, for instance, a system of simultaneous equations is contravariant in the variables.

https://www.jstor.org/stable/108572

kmill · on July 24, 2017

Next you're going to say "natural," "functor," and "category" come from category theory, too! :-)