“We ought to regard the present state of the universe as the effect of its antecedent state and as the cause of the state that is to follow. An intelligence knowing all the forces acting in nature at a given instant, as well as the momentary positions of all things in the universe, would be able to comprehend in one single formula the motions of the largest bodies as well as the lightest atoms in the world, provided that its intellect were sufficiently powerful to subject all data to analysis; to it nothing would be uncertain, the future as well as the past would be present to its eyes. The perfection that the human mind has been able to give to astronomy affords but a feeble outline of such an intelligence.”

“Another glorious Sierra day in which one seems to be dissolved and absorbed and sent pulsing onward we know not where. Life seems neither long nor short, and we take no more heed to save time or make haste than do the trees and stars. This is true freedom, a good practical sort of immortality.”

“A physicist that I know commented that many other scientific disciplines, such as geology, anthropology, astronomy, are also challenged by biblical fundamentalism, but their people seem to be able to get on with their work without worrying unduly. Only Darwinians seem thrown into a frenzy that sends them running to litigation and demanding censorship. His explanation was that it’s a rival religion.”

“I am, indeed, an absolute materialist so far as actual belief goes; with not a shred of credence in any form of supernaturalism—religion, spiritualism, transcendentalism, metempsychosis, or immortality.”

“My foregrounds are imaginary, my backgrounds real.”

“Will be but corpses dressed in frocks, who cannot speak to birds or rocks.”

“Intuition must be taken seriously in the absence of substantial theoretical understanding, but once such theoretical understanding begins to take shape, prior intuitive judgments carry little weight unless they have been endorsed by the progress of theory. The greater one’s theoretical understanding, the less weight one may assign to untutored judgment.All this applies equally well to the case of appeals to intuition in philosophy. We sometimes hear philosophers speak of some intuitions as ‘merely’ driven by theory, and thus to be ignored. While it is certainly true that judgments driven by bad theories are not to be taken seriously, the solution is not to try to return to some pure state of theory independent judgment, before the fall, as it were; rather the solution is to get a better theory. Intuition in the absence of theory does not count for nothing, especially if no credible theory is available. But this is not to award high marks to intuitive judgment before the arrival of successful theory, let alone after, when the initially low value of such judgment drops still lower.”

“The natural is so awesome that we need not go beyond it.”

“Science is opposed to theological dogmas because science is founded on fact. To me, the universe is simply a great machine which never came into being and never will end. The human being is no exception to the natural order. Man, like the universe, is a machine. Nothing enters our minds or determines our actions which is not directly or indirectly a response to stimuli beating upon our sense organs from without. Owing to the similarity of our construction and the sameness of our environment, we respond in like manner to similar stimuli, and from the concordance of our reactions, understanding is born. In the course of ages, mechanisms of infinite complexity are developed, but what we call ‘soul’ or ‘spirit,’ is nothing more than the sum of the functionings of the body. When this functioning ceases, the ‘soul’ or the ‘spirit’ ceases likewise.I expressed these ideas long before the behaviorists, led by Pavlov in Russia and by Watson in the United States, proclaimed their new psychology. This apparently mechanistic conception is not antagonistic to an ethical conception of life.”

“I am of old and young, of the foolish as much as the wise,Regardless of others, ever regardful of others,Maternal as well as paternal, a child as well as a man,Stuffed with the stuff that is course, and stuffed with the stuff that is fine, one of the nation, of many nations, the smallest the same and the the largest”

“If there is a Creator-God, it has used methods of creation that are indistinguishable from nature, it has declined to make itself known for all of recorded history, it doesn’t intervene in affairs on earth, and has made itself impossible to observe. Even if you believe in that God… why would you think it would want to be worshiped?”

“My atheism, like that of Spinoza, is true piety towards the universe and denies only gods fashioned by men in their own image, to be servants of their human interests.”

“Study, along the lines which the theologies have mapped, will never lead us to discovery of the fundamental facts of our existence. That goal must be attained by means of exact science and can only be achieved by such means. The fact that man, for ages, has superstitiously believed in what he calls a God does not prove at all that his theory has been right. There have been many gods – all makeshifts, born of inability to fathom the deep fundamental truth. There must be something at the bottom of existence, and man, in ignorance, being unable to discover what it is through reason, because his reason has been so imperfect, undeveloped, has used, instead, imagination, and created figments, of one kind or another, which, according to the country he was born in, the suggestions of his environment, satisfied him for the time being. Not one of all the gods of all the various theologies has ever really been proved. We accept no ordinary scientific fact without the final proof; why should we, then, be satisfied in this most mighty of all matters, with a mere theory?Destruction of false theories will not decrease the sum of human happiness in future, any more than it has in the past… The days of miracles have passed. I do not believe, of course, that there was ever any day of actual miracles. I cannot understand that there were ever any miracles at all. My guide must be my reason, and at thought of miracles my reason is rebellious. Personally, I do not believe that Christ laid claim to doing miracles, or asserted that he had miraculous power…Our intelligence is the aggregate intelligence of the cells which make us up. There is no soul, distinct from mind, and what we speak of as the mind is just the aggregate intelligence of cells. It is fallacious to declare that we have souls apart from animal intelligence, apart from brains. It is the brain that keeps us going. There is nothing beyond that.Life goes on endlessly, but no more in human beings than in other animals, or, for that matter, than in vegetables. Life, collectively, must be immortal, human beings, individually, cannot be, as I see it, for they are not the individuals – they are mere aggregates of cells.There is no supernatural. We are continually learning new things. There are powers within us which have not yet been developed and they will develop. We shall learn things of ourselves, which will be full of wonders, but none of them will be beyond the natural.[Columbian Magazine interview]”

“Shallow men believe in luck or in circumstance. Strong men believe in cause and effect.”