Student or Learner
Let's say you know an old man who is very moralistic and egotistical. He thinks he has all the answers to all the problems of all humans. He thinks if people listen to him and live the way he tells them to, they are going to be happy. Would you say this about him? :
He thinks he has a prescription for the happiness of all humankind.
Is this natural English? And would you completely understand it if someone used this sentence in a conversation with you?