"All that I've done in the above is to restate a simple principle: statically and dynamically typed languages enforce their types at different points in a program's life-cycle. Depending on whether you view things through a static or dynamic type prism, either class of language can be considered more expressive. Dynamically typed languages will try and execute type-unsafe programs; statically typed languages will reject some type-safe programs. Neither choice is ideal, but all our current theories suggest this choice is fundamental. Therefore, stating that one class of language is more expressive than the other is pointless unless you clearly state which prism you're viewing life through."