I like the architect/engineer analogy, to explain the dichotomy. I use it all the time, when my friends or relatives ask me to fix their computer. I tell them it's like calling an architect when your bathroom pipes get clogged.
It's a poor metaphor. I'm an engineer and I still call a plumber.
What I enjoy about Engineering is that you have a set of constraints and you have the challenge of working within those constraints to solve a problem in a feasible manner. All most everything can be boiled down to an optimization problem, make this reactor use less fuel, make this engine deliver more power, make this component lighter etc.
To create my own (bad) metaphor engineering is about coloring between the lines in the most efficient way possible. Science is what draws the lines and engineering is what fills them in.
