We should note that all of these places of thermal extremes (Finnish saunas, Japanese hot baths, American beaches and mountains) have their opposites close at hand. There are possibly two reasons for having the extremes right next to each other.
The first is physiological: the availability of extremes ensures that we can move from one to the other to maintain a thermal balance.
The second might be termed aesthetic: the experience of each extreme is made more acute by contrast to the other.
Works of art which have great life often have intense contrast within: rough/smooth, solid/void, loud/silent, empty/full. It is the difference between opposites which gives birth to something. Contrast is what often gives other principles their degree of life – the intensity of the boundary, the markedness of the alternating repetition.
Contrast strengthens centers by making each a deeper entity of itself, and thereby giving deeper meaning to both. It is, at its simplest, what allows us to differentiate. But meaningless contrast remains meaningless. It is only when centers are actively, mutually, and meaningfully composed that it acts to deepen the whole.
Sitting there in the Whitney's coffee shop, Irwin pointed through the glass wall up at the play of shadows on a building facade across the street. "That the light strikes a certain wall at a particular time of day in a particular way and it's beautiful," he commented, "that, as far as I'm concerned, now fits all my criteria for art."
At the terminus of Irwin's trajectory, when all the nonessentials had been stripped away, came the core assertion that aesthetic perception itself was the pure subject of art. Art existed not in objects but in a way of seeing.