From an interview with Wim Gilles in Origin of Things, reviewed previously (line breaks mine, to aid reading):
“How did you Design then, at the time?
Do you know the term heuristics? In science you pose a hypothesis, and it is true as long as you cannot prove that it isn’t (this is Karl Popper’s theory.) Science is therefore a process of verification. That is a bit of traditional scientific thinking, to draw a conclusion on the basis of establishing a few facts, and to deduce from all the facts that there appears to be a general rule. We call that a law.
Heuristics is based on a known piece of information. If you’re a carpenter, it is known (by passed down information) that you don’t hold a nail by its point, but rather with the point downwards. That has never been proved scientifically. You just do it like that. You’ll discover if it doesn’t work.
That is heuristics, an ancient Greek way of doing things that has been denied by science for centuries. You just do something. It’s a matter of trial and error. These is therefore a heuristics school and I belong to that school.”