Le Corbusier said so. Noone seems to understand it.
A window sill is not 1m above the floor. A window is properly located so its centre is 1.0 eyeheights above the floor and its size is 1.0 visionwidths, because man is the measure of all things. A good architect resolves these difficult units appropriately to the building.
The same applies to doors, stair steps, GUI animation times and technical writing. The reader's comprehension is the measure, not logical structure or the writer's composition ideal.