Liberty is the condition of duty, the guardian of conscience. It grows as conscience grows. The domains of both grow together. Liberty is safety from all hindrances, even sin. So that Liberty ends by being Free Will.
The past speaks to us in a thousand voices, warning and comforting, animating and stirring to action.
Happy indeed is the scientist who not only has the pleasures which I have enumerated, but who also wins the recognition of fellow scientists and of the mankind which ultimately benefits from his endeavors.