This booklet, The Canon of Reason and Virtue, is an extract from the author's larger work, Lao-Tze's Tao Teh King, and has been published for the purpose of making our reading public more familiar with that grand and imposing figure Li Er, who was honored with the posthumous title Poh-Yang, i. e.,Prince Positive (representing the male or strong principle); but whom his countrymen simply call Lao-tze, the Old Philosopher.