Form follows function

Form follows function is a principle associated with modernist architecture and industrial design in the 20th century. The principle is that the shape of a building or object should be primarily based upon its intended function or purpose.

The American architect Louis Sullivan coined the phrase, although the authorship of the phrase is often wrongly ascribed to the American sculptor Horatio Greenough, whose thinking to a large extent predates the later functionalist approach to architecture. Greenough's writings were for a long time largely forgotten, and were rediscovered only in the 1930s; in 1947 a selection of his essays was published under the title Form and Function: Remarks on Art by Horatio Greenough.

Sullivan, Greenough's much younger compatriot, who admired rationalist thinkers like Greenough, Thoreau, Emerson, Whitman and Melville, coined the phrase in his article The Tall Office Building Artistically Considered in 1896 (some fifty years after Greenough's death), though Sullivan later attributed the core idea to Marcus Vitruvius Pollio the Roman architect, engineer and author who first asserted in his book De architectura that a structure must exhibit the three qualities of firmitas, utilitas, venustas – that is, it must be solid, useful, beautiful. Here Sullivan actually said "form ever follows function", but the simpler (and less emphatic) phrase is the one usually remembered. For Sullivan this was distilled wisdom, an aesthetic credo, the single "rule that shall permit of no exception". The full quote is thus:

"Whether it be the sweeping eagle in his flight, or the open apple-blossom, the toiling work-horse, the blithe swan, the branching oak, the winding stream at its base, the drifting clouds, over all the coursing sun, form ever follows function, and this is the law. Where function does not change, form does not change. The granite rocks, the ever-brooding hills, remain for ages; the lightning lives, comes into shape, and dies, in a twinkling.
It is the pervading law of all things organic and inorganic, of all things physical and metaphysical, of all things human and all things superhuman, of all true manifestations of the head, of the heart, of the soul, that the life is recognizable in its expression, that form ever follows function. This is the law."

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