"What Is Man?", published by Mark Twain in 1906, is a dialogue between a young man and an older man jaded to the world. The title refers to Psalm 8-4,[citation needed] which begins 'what is man, that you are mindful of him...'. It involves ideas of destiny and free will, as well as of psychological egoism. The Old Man asserted that the human being is merely a machine, and nothing more. The Young Man objects, and asks him to go into particulars and furnish his reasons for his position. The work appears to be a genuine and an earnest debate of his opinions about human nature, rather than satirical. Twain held views similar to that of the old man prior to writing 'What is Man?'. However, he seems to have varied in his opinions of human freedom.