To our senses, the elements are four and have ever been, and will ever be for they are the elements of life, of poetry, and of perception, the four Great Ones, the Four Roots, the First Four of Fire and the Wet, Earth and the wide Air of the World. To find the other many elements, you must go to the laboratory and hunt them down. But the four we have always with us, they are our world. Or rather, they have us with them.
The human understanding is moved by those things most which strike and enter the mind simultaneously and suddenly, and so fill the imagination; and then it feigns and supposes all other things to be somehow, though it cannot see how, similar to those few things by which it is surrounded.
If you are only skeptical, then no new ideas make it through to you. You become a crotchety old person convinced that nonsense is ruling the world. (There is, of course, much data to support you.) But every now and then, a new idea turns out to be on the mark, valid and wonderful. If you are too much in the habit of being skeptical about everything, you are going to miss or resent it, and either way you will be standing in the way of understanding and progress.
The human understanding is of its own nature prone to suppose the existence of more order and regularity in the world than it finds. And though there be many things in nature which are singular and unmatched, yet it devises for them parallels and conjugates and relatives which do not exist. Hence the fiction that all celestial bodies move in perfect circles, spirals and dragons being (except in name) utterly rejected.
The Darwinian movement has made no difference to mankind, except that, instead of talking unphilosophically about philosophy, they now talk unscientifically about science.
Conscientious and careful physicians allocate causes of disease to natural laws, while the ablest scientists go back to medicine for their first principles.
My parents were not scientists. They knew almost nothing about science. But in introducing me simultaneously to skepticism and to wonder, they taught me the two uneasily cohabiting modes of thought that are central to the scientific method.
As agonizing a disease as cancer is, I do not think it can be said that our civilization is threatened by it. ... But a very plausible case can be made that our civilization is fundamentally threatened by the lack of adequate fertility control. Exponential increases of population will dominate any arithmetic increases, even those brought about by heroic technological initiatives, in the availability of food and resources, as Malthus long ago realized.
We are not clear as to the role in life of these chemicals; nor are we clear as to the role of the physician. You know, of course, that in ancient times there was no clear distinction between priest and physician.
The nation behaves well if it treats the natural resources as assets which it must turn over to the next generation increased; and not impaired in value.
We may climb into the thin and cold realm of pure geometry and lifeless science, or sink into that of sensation. Between these extremes is the equator of life, of thought, or spirit, or poetry,--a narrow belt.