Tutor. For what purpose then do you suppose those orbs were designed?
Pupil. Indeed, I cannot tell.
Tutor. You surely cannot imagine that they were intended for our use, since we knew nothing of them till after the invention of telescopes.
Pupil. That is what I think no one can suppose.
Tutor. And do not all the planets enjoy the benefit of the sun in common with us?
Pupil. Undoubtedly.
Tutor. Well, then; of what use would the light and heat be which is conveyed to them from the sun; or the light which they receive from their moons if there are no inhabitants?
Pupil. I know of none.
Tutor. Can you then have any doubt about their being inhabited?
Pupil. No, Sir.—But you say that the stars are suns, each of which is the center of a system of planets or worlds.