From Musashi's *Book of Five Rings* (1643), via Marshall: the master carpenter (foreman) succeeds by matching each material to the purpose it is suited for. Straight, unknotted, good-looking timber becomes the pillars; slightly weaker but attractive wood goes where it shows but bears no load; strong-but-flawed wood becomes hidden inner supports; weak, knotted wood serves as scaffolding and is later burned for firewood. Nothing is wasted; nothing is forced into a role it cannot hold. The same foreman "allots his work according to the abilities of his men" and attends to their morale. Musashi's claim: this *is* the principle of strategy. Marshall generalizes it across life — impulse control, swordsmanship, and carpentry differ on the surface but "share underlying principles of applying the right thing to the right purpose." The skill is diagnosis: see the true qualities of a material, a person, or a moment, and deploy it where those qualities fit. Cross-domain: team design and role-fit, resource allocation, casting, portfolio construction. --- *Source: [[Book Inventory/Progression|Progression]] (Sebastian Marshall, 2016) — Upstream Effects #9 — Adherence and Mastery*