"All we need to know is a little of the world about us, a little of the race and its history, and a little of the other worlds out in space, all of which is open to anybody who will seek it.

The rest is simply a little connected thought.

Reason tells me that there can be no limits to time or space or intelligence.

Time always has been, there can be no end to space, and intelligence cannot create itself.

Now, with limitless time and space and intelligence to work with, what have we?
The human mind, being limited, cannot grasp the limitless; therefore, we must make arbitrary points of beginning and ending.