Leonardo.

"Although human subtley makes a variety of inventions... it will never devise an invention more beautiful, more simple or more direct than does nature, because in her inventions nothing is lacking and nothing is superfluous."

The great man has been my hero since childhood. Here we lie, sit and stand, on a planet, mixed up blobs of carbon and water with no apparent purpose beyond the furthering of our own existence; beautifully designed nonetheless so to do. Carbon and water...

Not many people are aware of the degree of mischief in Leonardo's humour. One of his subtlest jokes is illustrated in the 1483 picture "Madonna of the Rocks". He repeated the trick a second time in 1506, so obviously meant it to be. Among the religious dignitaries who commissioned this work, who would dare comment or point out this (mildly pornographic) joke? You will never see this picture in quite the same way again.