Category theory offered programming insights in 1965

(written by Lawrence Krubner, however indented passages are often quotes)

I just got done reading John Derbyshires book, The Unknown Quantity, which is a history of algebra. Derbyshire starts with the Babylonians in 2000 BC and then he narrates the advances in algebra up to modern times (to 2006). He sounds somewhat skeptical about whether or not Category Theory ever had any practical usefulness. However, this article from 1965 seems to suggest that, yes, Category Theory did at one offer some practical insights into programming. I am using the word “practical” in an expansive sense, since even in 2010, few programmers ground their praxis on Category Theory.