A look at the history of Dennis Ritchie’s dissertation. Via a Hacker News Discussion. Article includes links to two versions: his personal copy and one by Albert Meyer.
On Ritchie’s personal web pages at the Labs (still maintained by Nokia, the current owner), he writes with characteristic dry deprecation of his educational journey into computing:
“I . . . received Bachelor’s and advanced degrees from Harvard University, where as an undergraduate I concentrated in Physics and as a graduate student in Applied Mathematics . . . The subject of my 1968 doctoral thesis was subrecursive hierarchies of functions. My undergraduate experience convinced me that I was not smart enough to be a physicist, and that computers were quite neat. My graduate school experience convinced me that I was not smart enough to be an expert in the theory of algorithms and also that I liked procedural languages better than functional ones.”1
Whatever the actual merits of these self-evaluations, his path certainly did lead him into a field and an environment in which he made extraordinary contributions.