Willy Ley

Ideas, like large rivers, never have just one source.

The point to remember is that a giant leap into space can be a giant leap toward peace down below.

The study of an idea is, of necessity, the story of many things.

Why should we try for space travel? It cannot be a substance of any kind that can be expected to pay. It can only be something intangible, not involving haulage, which is at the same time more valuable. There is something like that: Knowledge.

Just as the water of a river near its mouth, in its final form, is composed largely of many tributaries, so an idea, in its final form, is composed largely of later additions.