Scientists are driven forward in their search for knowledge of nature by the same sort of urge within themselves that imbued the geographical explorers of the past to search for new lands and new continents. But they have to work in totally different fields. They are concerned either with the extreme smallness of the inside of the atom, with the enormous grandeur of the universe as a whole, or with the tremendous complexity of matter gathered together in what we call the living form.
Now, all the knowledge that we gain in these fields can be used, and is used, for the good of mankind, but it can equally well be used in war or in other ways to his detriment. I am very conscious of this fact and feel very strongly that one of the duties of the scientist today is to tell the world about these two sides to the fruits of science, and to try to convince him that he must follow the right path, the path of utilisation for the good of mankind. And I emphasise mankind, rather than of himself or his nation, and to endeavour to give to all people the fruits that knowledge brings.
This earth of ours is but one tiny speck in the immense universe in which it exists. It is one of the intriguing tasks of science to try to find out what exists in the universe, and in particular whether there are sentient beings anywhere else with whom we can communicate and with whom we can exchange experience.