I think you misunderstood the article. He knows exactly what the components allow him to accomplish, he just doesn't know how exactly they work or any of the ma

I think you misunderstood the article. He knows exactly what the components allow him to accomplish, he just doesn't know how exactly they work or any of the math behind them. This is directly analogous to the situation in every other programming language: very few programmers know exactly how every library that they use works. This is good, because in practice there isn't time to learn the intricacies of every one of your dependencies. To be clear, this also has very little to do with Haskell. kan-extensions is a library, it's not a part of Haskell itself. His point is that if you had a kan-extensions package in some other language, it would be a hell of a lot more difficult to use it in your program without learning the math yourself. And again, the key point here isn't that you can gloss over what the library allows you to do, it's that you can gloss over the complex abstract mathematics that went into the creation of the library. You can get the benefits of free monads without taking a course in category theory. That's definitely a good thing.