Science is the one human activity that is truly progressive. The body of positive knowledge is transmitted from generation to generation.

I knew that even if I were second or third rate, it was astronomy that mattered.

All nature is a vast symbolism: Every material fact has sheathed within it a spiritual truth.

The history of astronomy is a history of receding horizons.

Observations always involve theory.

At the last dim horizon, we search among ghostly errors of observations for landmarks that are scarcely more substantial. The search will continue. The urge is older than history. It is not satisfied and it will not be oppressed.

Past time is finite, future time is infinite.