What is a number that man may know it, and man that he may know a number? (1960) [pdf]

I wonder if some folks here might not know that this is by the coauthor of McCulloch and Pitts (1943) A logical calculus of the ideas immanent in nervous activity, which started the study of Neural Nets and was also Kleene's inspiration for starting the study of Finite State machines.

(And, forgive me, I can't resist linking to a wonderful article about Pitts, http://nautil.us/issue/21/information/the-man-who-tried-to-r...)