P: These are the only two paths available to him. 
Q: All humans are bestowed with a conscience that helps us discriminate between good and bad, eternal and non eternal.
R: Although all living species are involved in sleeping, mating, defending and eating, only humans as far as we know-can think and decide what is eternally beneficial to them.
S: Based on this special quality a human can decide whether he wants to tread the path of eternal welfare or sensual enjoyment.