You know the rules. No Google searches! Winner gets a beer on me when/if s/he is ever nearby :)
Whoever chooses a vocation which he esteems highly will carefully avoid making himself unworthy of it; therefore, he will act nobly because his position in society is noble.
The main principle, however, which must guide us in the selection of a vocation is the welfare of humanity, our own perfection. One should not think that these two interests combat each other, that the one must destroy the other. Rather, man’s nature makes it possible for him to reach his fulfillment only by working for the perfection and welfare of his society.
If a person works only for himself he can perhaps be a famous scholar, a great wise man, a distinguished poet, but never a complete, genuinely great man.
History calls those the greatest men who ennobled themselves by working for the universal. Experience praises as the most happy the one who made the most people happy. Religion itself teaches us that the ideal for which we are all striving sacrificed itself for humanity, and who would dare to destroy such a statement?
When we have chosen the vocation in which we can contribute most to humanity, burdens cannot bend us because they are only sacrifices for all. Then we experience no meager, limited, egotistic joy, but our happiness belongs to millions, our deeds live on quietly but eternally effective, and glowing tears of noble men will fall on our ashes.