[dragonwriter]

That essay is generally good, and I agree with the general point (quoting: "object-oriented programming is a useful technique in some cases, but it isn't something that has to pervade every program you write"), but the specific quote you pull out is quite bizarre, given that "defining new types" has nothing at all do with OOP. It has more to do with statically-typed programming -- idiomatic code does a lot more of it (even equating "class" with "type", which is a dubious equivalence outside of statically-typed OO languages) in a statically-typed functional programming language like Haskell than in a dynamically-typed OO language like Ruby.