Who knows whether the spirit of man goes upward and the spirit of the beast goes down into the earth?
Solomon is still showing that every thing in this world, without piety and the fear of God, is vanity. Take away religion, and there is nothing valuable among men, nothing for the sake of which a wise man would think it worth while to live in this world.
Commenting on Ecclesiastes 3:16-22
Who knoweth the spirit of man that goeth upward?.... There is indeed a difference between a man and a beast; though they have one breath, they have not one spirit or soul; man has a rational and immortal soul, which, when he dies, goes upwards to God that gave it; to be judged by him, and disposed of by him, in its proper apartment, until...
Who knoweth--Not doubt of the destination of man's spirit (Ecc 12:7); but "how few, by reason of the outward mortality to which man is as liable as the beast and which is the ground of the skeptic's argument, comprehend the wide difference between man and the beast" (Isa 53:1).