There is no greater happiness than to be occupied with good, whether it be good thoughts, good actions, or good employment; for every good thing is fraught with bliss, and evil cannot enter the heart or house that is tenanted by all that is good. The mind whose doors are guarded by good shuts out unhappiness as the well-sentries garrison shuts out the foe. Unhappiness can only enter through unguarded doors, and even then its power over the tenant is not complete unless it finds him occupied with evil. Not to entertain evil thoughts; not to do bad actions; not to engage in worthless or questionable employment, but to resort to good in all things—this is the source of supreme happiness.