Historical chronology, human or geological, depends... upon comparable impersonal principles. If one scribes with a stylus on a plate of wet clay two marks, the second crossing the first, another person on examining these marks can tell unambiguously which was made first and which second, because the latter event irreversibly disturbs its predecessor. In virtue of the fact that most of the rocks of the earth contain imprints of a succession of such irreversible events, an unambiguous working out of the chronological sequence of these events becomes possible.

[The] first postulate of the Principle of Uniformity, namely, that the laws of nature are invariant with time, is not peculiar to that principle or to geology, but is a common denominator of all science. In fact, instead of being an assumption or an ad hoc hypothesis, it is simply a succinct summation of the totality of all experimental and observational evidence.

History, human or geological, represents our hypothesis, couched in terms of past events, devised to explain our present-day observations.

It is hard to know which is the more remarkable- that it took 600 million years for the Earth to make its oil, or that it took 300 years to use it up.

The steep ride up the and down the energy curve is the most abnormal thing that has ever happened in human history. Most of human history is a no-growth situation. Our culture is built on growth and that phase of human history is almost over and we are not prepared for it. Our biggest problem is not the end of our resources. That will be gradual. Our biggest problem is a cultural problem. We don't know how to cope with it.

Our ignorance is not so vast as our failure to use what we know.

Historical chronology, human or geological, depends... upon comparable impersonal principles. If one scribes with a stylus on a plate of wet clay two marks, the second crossing the first, another person on examining these marks can tell unambiguously which was made first and which second, because the latter event irreversibly disturbs its predecessor. In virtue of the fact that most of the rocks of the earth contain imprints of a succession of such irreversible events, an unambiguous working out of the chronological sequence of these events becomes possible.