The Sum of All Wisdom

Shakespeare did a fair job of summing up wisdom with lines from Hamlet.  Polonius admonishes Laertes, "This, above all, to thine own self be true, then it must follow as the night, the day, thou canst not then be false to any man."  The truth is that the actual sum of all wisdom is contained in the following concept:  Love yourself and all other creatures as you should love God.  Abide by that one rule and you will change the universe.