ABSTRACT In the late 1920’s linguists Edward Sapir and Benjamin Whorf hypothesized that … all » the thoughts we can think are largely determined by the language we speak. In his essay “Beating the Averages” Paul Graham echoed this notion and invented a hypothetical language, Blub, to explain why it is so hard for programmers to appreciate programming language features that aren’t present in their own favorite language. Does the Sapir-Whorf hypothesis hold for computer languages? Can you be a great software architect if you only speak Blub? Doesn’t Turing equivalence imply that language choice is just another implementation detail? Yes, no, and no says Peter Seibel, language lawyer (admitted, at various times, to the Perl, Java, and Common Lisp bars) and author of the award-winning book _Practical Common Lisp_. In his talk, Peter will discuss how our choices of programming language influences and shapes our pattern languages and the architectures we can, or are likely to, invent. He will also discuss whether it’s sufficient to merely broaden your horizons by learning different programming languages or whether you must actually use them.