Three basic shapes beloved of humans, no doubt for their simplicity, are the square, circle and triangle. “Man is symbolized by three elements, one on top of another: pyramid—square— circle,” said Zoroaster.
In his book Kami no Michi Yukitaka Yamamoto, the 96th hereditary priest of Tsubaki Shrine in Mie Prefecture, wrote: “The Principle of ‘Sanmi–Sangen‘ explains the mystery of life. Sanmi–Sangen means the three elements that constitute the basis of all forms of existence. These basic symbols both explain the meaning of and guide the destiny of human life. We can see Sanmi–Sangen operate at many levels.”
I’m unable to identify where the Sanmi-Sangen theory originated from, but the founder of aikido, Ueshiba Morihei, put forward similar ideas:
“The body should be triangular, the mind circular. The triangle represents the generation of energy and is the most stable physical posture. The circle symbolizes serenity and perfection, the source of unlimited techniques. The square stands for solidity, the basis of applied control.”
If you check out this page, you can see all kinds of attributes have been allocated to the three shapes, including (oddly to my mind) the suggestion that the square stands for the Sun God Amaterasu, the circle for the Moon God Tsukuyomi no Mikoto, and the triangle for the God of the Stars, Susanoo-no-Mikoto.
Interestingly, a garden in the Zen monastery of Kennin-ji claims to be based on the square, circle, triangle motif. An accompanying notice says it is based on work by Sengai Gibon (1750 – 1837) [see left]. “One of his famous paintings,” says Wikipedia, “shows a circle, a square and a triangle. Sengai left the painting without a title or inscription (save for his signature), however the painting is often called “The Universe” when referred to in English.”
The painting has long puzzled people. The ink tones vary from grey to black, and the three shapes overlap as if to suggest interconnection between them. D.T. Suzuki, who introduced Zen to the West, interpreted Sengai’s painting to represent formlessness and infinity, in accord with his view of emptiness as the essence of enlightenment. (See here for his interpretation.)
So it would appear that Ueshiba took his idea from Zen. And when you look closer at Ueshiba’s thought, it is striking how close to the thinking of Zen it is. Suppress the ego. Discipline your mind. Understand the oneness of all things. Get back to basic purity (or in Zen terms Buddha nature).
It’s often said that Ueshiba derived his thinking from Omoto-kyo. I can’t help feeling that, as with other martial arts, Zen was a strong influence too. Or perhaps it’s simply the case that in the strongly syncretic world of Japanese religion it’s sometimes impossible to separate the strands.