An engineer, a physicist, a mathematician, and a philosopher

An engineer, a physicist, a mathematician, and a philosopher are at a coffee house.

The physicist says, “You know, engineering is just applied physics,” and they all laugh. The mathematician says, “You know, physics is just applied math,” and they all laugh again. Then the philosopher says, “Well, you know, math is just applied philosophy,” and the engineer says, “Shut up and make our coffee.”