A weld bead laid too fast looks finished but fails inspection — it has the shape of good work without the structure. The philosopher Charles Sanders Peirce spent his career distinguishing between beliefs that merely feel settled and beliefs that can actually bear load. His insight: most of what we call 'knowing how' in a skilled trade is a web of habits reinforced by success, which is not the same thing as understanding *why* the success holds. The weld that's worked a hundred times in mild steel will crack in chrome-moly if you never interrogated the underlying metallurgy. Peirce called this the difference between the 'irritation of doubt' — the productive discomfort that drives genuine inquiry — and the mere absence of doubt, which is just comfort wearing the mask of competence. This Monday, carry one assumption into your work that you've never actually tested — about a fit-up tolerance, a preheat spec, a rigging habit — and ask what would break it.

What is one procedure you follow reliably but couldn't fully explain if a younger tradesperson asked you *why* — not how, but why?

Drawing from American Pragmatism (Peircean Inquiry Theory) — Charles Sanders Peirce ("The Fixation of Belief," Popular Science Monthly, 1877)