Card 1 of 8: Form Follows Function
Sullivan coined the modernist movement's founding rule in a single 1896 essay: form ever follows function. Strip away ornament that doesn't serve a purpose, and the true shape of a thing reveals itself.
Gibson's 1966 idea reframed perception itself: you don't see a chair and deduce you can sit on it — the 'sit-ability' is part of what you perceive directly. He called this an affordance.
Norman's bestseller is built on a doormat of complaints: doors you push when they say pull, stovetops where you burn the wrong burner — not bad users, bad signifiers.
In the 1970s Rams watched Braun's catalog swell with trendy radios and wrote a checklist on a single sheet: if a product fails any of ten principles, it is not good design.
Christensen's milkshake study flipped briefs: McDonald's wasn't competing with Burger King for breakfast; the morning milkshake was hired to make a boring commute feel less boring and to last until lunch.
Conway wrote in Datamation in 1967: any organization that designs a system will produce a design whose structure copies its own communication structure. The org chart is the blueprint.
John Gall opened Systemantics with a one-liner engineers quote weekly: a complex system that works always evolved from a simple system that worked.
Loewy, who designed everything from Greyhounds to the Coca-Cola bottle, kept a gauge: MAYA. Be as advanced as possible, but not so advanced that it stops feeling acceptable.