Comment by kragen

Maybe if developing large-scale software starting with the formal methods we have today is just a fantasy—and that's plausible—we shouldn't be trying to formalize "software engineering". Imagine trying to formalize medicine before Pasteur, motor engineering before Carnot, mechanical engineering before Reuleaux, or structural engineering before Galileo. Today, we do have relevant bodies of formal knowledge that are enough to help someone get started with a project in those areas and succeed at it. As you say, that knowledge doesn't exist yet for software.

So what would you teach an architect in 01530 or a mechanical engineer in 01850? In addition to the relatively sparse formal knowledge that did exist, you'd make them study designs that are known to have worked, you'd apprentice them to currently successful master architects or mechanical engineers, and you'd arrange for their apprenticeship to give them experience doing the things people already do know how to do.