I've included in a few pages of Reckonings, especially those related to my and others' thoughts of spirituality and the practice of meditation, an image called an ensō. A friend with whom I was talking today explained to me what an ensō is, and has drawn many of them herself. There is also a short Wikipedia entry about ensō, at https://en.wikipedia.org/wiki/Ens%C5%8D.
I especially enjoyed the Wikipedia author's remark, "A person draws the ensō in one fluid, expressive stroke. When drawn according to the sōsho (草書) style of Japanese calligraphy, the brushstroke is especially swift. Once the ensō is drawn, one does not change it. It evidences the character of its creator and the context of its creation in a brief, continuous period of time. Drawing ensō is a spiritual practice...."
Here are two more ensōs: