As a result there are many public roles available for consideration which can be roughly placed into categories instructive to our choice. These include occupations with tangible outputs, callings with more limited measurability, entertainment with the added potential of fame, missionary work with the possibility inclusive of supererogatory duty, politics and positions of influence with their larger impact, and practical scientists and creators with hope of a more enduring legacy. Nonetheless the sense and magnitude of purpose of any given role is ultimately subjective and thus any category can be highly meaningful or seemingly futile to the actor.
Since societal purpose is a choice it follows a decision process is needed. Key decision factors fall into three groups: individual (physical and mental), external (geographic, political, cultural, historical, and future-directed), and intrinsic (size, quantity, proportion of contribution, measurability, and likelihood of success). Table 6 in the Appendix on this site presents a practical process for factoring these variables.
Next comes success factors which include commitment, patience or time, flexibility, enjoyment, realistic expectations, and intention. Unfortunately while societal purpose is critical to a meaningful life and perhaps even to happiness, it is precarious even for the talented among us. Employing in full the factors in success is the best means to find one’s way in the murky waters of human significance.
At the end of the day, the benefits of societal purpose – subsistence, self-fulfillment, value to others, and legacy – make it worth the extreme effort it demands. 
Perseverance in an authentic role in the world is a source of ultimate satisfaction, a defining characteristic of our species, and the source of all human progress. And we need not despair of imagined insignificance as long as we remember the sagacious words of Lucian: “The life of the ordinary man is the best and most prudent choice. Cease from the folly of metaphysical speculation into origins and ends; count all this clever logic as idle talk and pursue one end alone – how you may do what your hands find to do, go your way with never a passion and always a smile.” Good advice in antiquity and today.
