Former President of Harvard University Charles W. Eliot wrote in his introduction to the Harvard Classics, ”In my opinion, a five-foot shelf would hold books enough to give a liberal education to any one who would read them with devotion, even if he could spare but fifteen minutes a day for reading.” Here you are, you can easily listen to his entire 15-minutes a day study guide while commuting to and from work (most of us spend far more than 15 minutes a day commuting each day), doing mundane work in the office, washing dishes at home, or doing most of the...