Robert Owen? Elbert Hubbard? Orlando K. Fitzsimmons? Sidney Abram Weltmer? O. A. Hawkins? Anonymous? Dear Quote Investigator: An optimistic rhyming maxim highlights the enormous potential for positive accomplishments. Here are three versions: (1) What humanity can conceive, humanity can achieve. (2) What man can conceive, man can achieve (3) Man can achieve what man can …