"Skilled manual labor entails a systematic encounter with the material
world, precisely the kind of encounter that gives rise to natural
science. From its earliest practice, craft knowledge has entailed
knowledge of the “ways” of one’s materials—that is, knowledge of their
nature, acquired through disciplined perception and a systematic
approach to problems. And in fact, in areas of well-developed craft,
technological developments typically preceded and gave rise to advances
in scientific understanding, not vice versa. The steam engine is a good
example. It was developed by mechanics who observed the relations
between volume, pressure, and temperature. This at a time when
theoretical scientists were tied to the caloric theory of heat, which
later turned out to be a conceptual dead end. The success of the steam
engine contributed to the development of what we now call classical
thermodynamics. This history provides a nice illustration of a point
made by Aristotle:
Lack of experience diminishes our power of taking a comprehensive
view of the admitted facts. Hence those who dwell in intimate
association with nature and its phenomena are more able to lay down
principles such as to admit of a wide and coherent development;
while those whom devotion to abstract discussions has rendered
unobservant of facts are too ready to dogmatize on the basis of a
few observations.
Another example is the Vernier scale used on machinists’ calipers and
micrometers. Invented in 1631, it is a sort of mechanical calculus that
renders continuous measurement in discrete digital approximation to four
decimal places. Such inventions capture a reflective moment in which
some skilled worker has made explicit the assumptions that are implicit
in his manual skill."