The clarity of simple thinking!

I love reading/hearing/seeing Alan Kay!

Today, science (a concern with what is real) is mixed with mathematics (a concern with what is true) is mixed with engineering (a concern with how something can be made). Each worker in each of these fields also partly works in the other two. Each field has a different temperament associated with it: mathematicians tend to be idealists, scientists realists, and engineers pragmatists. And each finds themselves temporarily adopting a borrowed temperament when they use the other areas to aid advances in the one they most love.

So saith the man in the foreword to Mark Guzdial's Squeak: Object-Oriented Design With Multimedia Applications, (Prentice-Hall, 2001).