"In science, if you know what you are doing, you should not be doing it. In engineering, if you do not know what you are doing, you should not be doing it. Of course, you seldom, if ever, see either pure state."

How can we design systems when we don't know what we're doing?

The most exciting engineering challenges lie on the boundary of theory and the unknown. Not so unknown that they're hopeless, but not enough theory to predict the results of our decisions. Systems at this boundary often rely on emergent behavior — high-level effects that arise indirectly from low-level interactions.

When designing at this boundary, the challenge lies not in constructing the system, but in understanding it. In the absence of theory, we must develop an intuition to guide our decisions. The design process is thus one of exploration and discovery.