Wisdom cannot be directly transmitted, and does not readily accumulate through the ages.

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.

Equipped with his five senses, man explores the universe around him and calls the adventure Science.

Not until the empirical resources are exhausted, need we pass on to the dreamy realms of speculation.

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

Astronomy is something like the ministry. No one should go into it without a call. I got that unmistakable call, and I know that even if I were second-rate or third-rate, it was astronomy that mattered.

With increasing distance, our knowledge fades, and fades rapidly. Eventually, we reach the dim boundary-the utmost limits of our telescopes. There, we measure shadows, and we search among ghostly errors of measurement for landmarks that are scarcely more substantial. The search will continue. Not until the empirical resources are exhausted, need we pass on to the dreamy realms of speculation.