That lower one also, not larger than a thumb, but brilliant like the sun, who is endowed with personality and thoughts, with the quality of mind and the quality of body, is seen small even like the point of a goad.

In plain words: This individual soul is described as no bigger than a thumb, yet bright like the sun. It has a sense of 'I', thoughts, a mind and a body. It can also seem as tiny as the point of an animal driver's stick.