When I was an undergraduate, in an acting class that I’d enrolled in as an elective, out of interest and for fun, our professor would have us practice, at the beginning of each meeting, twenty to thirty minutes of a very slow form of tai chi, which involved, in the rhythm and circularity of its movements, the summoning of this energy known as qi, the purpose of which, according to our professor, was both to relax us and to increase our ability to focus.