1) The document discusses the concept of earnestness and how the certainty of death and uncertainty of the timing of death can help a person learn earnestness. 2) It describes how focusing on the uncertainty of when death may come can motivate a person to earnestly seize the present day and avoid procrastination. 3) It also explains how contemplating death can help a learner focus on mastering a subject by pointing out the importance while also leaving open possibilities, just as the uncertainty of death does.