Who does not know history's first law to be that an author must not dare to tell anything but the truth? And its second that he must make bold to tell the whole truth? That there must be no suggestion of partiality anywhere in his writings? Nor of malice?
O philosophy, life's guide! O searcher-out of virtue and expeller of vices! What could we and every age of men have been without thee? Thou hast produced cities; thou hast called men scattered about into the social enjoyment of life.
[Lat., O vitae philosophia dux! O virtutis indagatrix, expultrixque vitiorum! Quid non modo nos, sed omnino vita hominum sine et esse potuisset? Tu urbes peperisti; tu dissipatos homines in societatum vitae convocasti.]
But if you should take the bond of goodwill out of the universe no house or city could stand, nor would even the tillage of the fields abide. If that statement is not clear, then you may understand how great is the power of friendship and of concord from a consideration of the results of enmity and disagreement. For what house is so strong, or what state so enduring that it cannot be utterly overthrown by animosities and division?