Now any study of the program or compiler source code will not show any vulnerability, but compiling the program will make a vulnerable program, and recompiling the compiler from its clean source code will not fix the situation.

This carrying down of a pattern which is not written down anywhere, a flaming torch lighting a torch lighting a torch, is analogous to four billion years of life on Earth. We talk like DNA is an everything-code that defines a human and a human brain, but it’s the implicit behaviour of cells (‘compiler’) and the mechanisms inside them which interpret DNA. The unbroken chain of life getting more and more complex and never being restarted from scratch, with the behaviours not written down anywhere for us to study. How does DNA arrange for x, y, z to happen? Maybe it doesn’t at all.

Accidentally stumbling on a mechanism that is simple enough to be recreated with every human birth might be possible, accidentally stumbling on a mechanism that took evolution billions of years to find and which it has hung onto by copying it and has never recreated it from scratch, could be much less likely, in a much bigger search space.