Every scientist, through personal study and research, completes himself and his own humanity. ... Scientific research constitutes for you, as it does for many, the way for the personal encounter with truth, and perhaps the privileged place for the encounter itself with God, the Creator of heaven and earth. Science shines forth in all its value as a good capable of motivating our existence, as a great experience of freedom for truth, as a fundamental work of service. Through research each scientist grows as a human being and helps others to do likewise.

However, the small probability of a similar encounter [of the earth with a comet], can become very great in adding up over a huge sequence of centuries. It is easy to picture to oneself the effects of this impact upon the Earth. The axis and the motion of rotation changed; the seas abandoning their old position to throw themselves toward the new equator; a large part of men and animals drowned in this universal deluge, or destroyed by the violent tremor imparted to the terrestrial globe.

The test of a theory is its ability to cope with all the relevant phenomena, not its a priori 'reasonableness'. The latter would have proved a poor guide in the development of science, which often makes progress by its encounter with the totally unexpected and initially extremely puzzling.

The way in which the persecution of Galileo has been remembered is a tribute to the quiet commencement of the most intimate change in outlook which the human race had yet encountered. Since a babe was born in a manger, it may be doubted whether so great a thing has happened with so little stir

The work of the inventor consists of conceptualizing, combining, and ordering what is possible according to the laws of nature. This inner working out which precedes the external has a twofold characteristic: the participation of the subconscious in the inventing subject; and that encounter with an external power which demands and obtains complete subjugation, so that the way to the solution is experienced as the fitting of one's own imagination to this power.

When I arrived in California to join the faculty of the New University which opened in October 1891, it was near the end of the dry season and probably no rain had fallen for three or four months. The bare cracked adobe fields surrounding the new buildings ... offered a decidedly unpromising outlook... A month or two later, however, there was a magical transformation. With the advent of the autumn rains the whole country quickly turned green, and a profusion of liverworts such as I had never seen before appeared on the open ground... I soon realized that right in my own backyard, so to speak, was a wealth of material such as I had never imagined would be my good fortune to encounter. ... Such an invitation to make a comprehensive study of the structure and development of the liverworts could not be resisted; and the next three years were largely devoted to this work which finally resulted in the publication of 'The Mosses and Ferns' in 1895.