Conjecture

Craft pride stopped knowledge moving. Each worker learned his own method over a long apprenticeship, so no two worked by the same rules of thumb, and because the work was seen as an art rather than a job, men kept their methods secret and believed them superior. Part I's conclusion: these organisational practices precluded efficient transmission of knowledge and skill, making it harder to improve at a craft or pick one up at all. The knowledge existed and could not travel.

Human nature