Of course not. You can certainly learn all you need to know on your own. However, that doesn't make the process of learning any easier. If you can get into a PhD program, it is a wonderful way to get access to information of various sorts.

If not, then the new free CS courses that are now being offered by Stanford and others provide extra help beyond reading books and papers. I'd highly recommend trying some!

When I heard the first couple of videos of Rich, I also asked myself this question. Here's Matt Welsh's take on "Do you need a PhD"?: http://matt-welsh.blogspot.co.at/2012/03/do-you-need-phd.htm...

I would say no, but a good chunk of knowledge is (though probably less is required than imagined) and if the academic methods of acquiring knowledge suit you (for many hackers they don't) then a Ph.D is a fine way to get a good chunk of knowledge. Here's Rich Hickey's recommended reading for Clojure specifically: http://www.amazon.com/Clojure-Bookshelf/lm/R3LG3ZBZS4GCTH/re... It's not exhaustive for even functional programming and design let alone the entirety of computer science, but it's certainly a good chunk of knowledge enough to do awesome work from.

Rich Hickey never went to school for Computer Science as far as I know. He studied music composition.