A Priori Quotes & Sayings

Many things would be changed for Americans if they would only admit that there is ill-luck in this world and that misfortune is not a priori a crime. — Simone De Beauvoir

We can be sure, he [Kant] says, that anything we shall ever experience must show the characteristics affirmed of it in our a priori knowledge, because these characteristics are due to our own nature, and therefore nothing can ever come into our experience without acquiring these characteristics. — Bertrand Russell

There are certain questions that scientists may not ask, or, more accurately, for some questions, there are certain answers that scientists must a priori preclude from consideration. — Satoshi Kanazawa

2.223 In order to discover whether the picture is true or false we must compare it with reality. 2.224 It cannot be discovered from the picture alone whether it is true or false. 2.225 There is no picture which is a priori true. — Ludwig Wittgenstein

[A]s a graduate student at Columbia University, I remember the a priori derision of my distinguished stratigraphy professor toward a visiting Australian drifter [a supporter of the theory of continental drift]. [ ... ] Today [ ... ] my own students would dismiss with even more derision anyone who denied the evident truth of continental drift a prophetic madman is at least amusing; a superannuated fuddy-duddy is merely pitiful. — Stephen Jay Gould

As Mr. R. U. Sayee has well said: 'It should be clear a priori that fairy lore must have developed as a result of modifications and accretions received in different countries and at many periods, though we must not overlook the part played by tradition in providing a mould that to some extent determines the nature of later additions.' It must also be self-evident that a great deal of confusion has been caused by the assumption that some spirit-types were fairies which in a more definite sense are certainly not of elfin provenance. In some epochs, indeed, Faerie appears to have been regarded as a species of limbo to which all 'pagan' spirits - to say nothing of defeated gods, monsters, and demons - could be banished, along with the personnel of Olympus and the rout of witchcraft. Such types, however, are usually fairly easy of detection. — Lewis Spence

Extremely unlikely events occur every moment and it is not a priori unthinkable that the evolution of life should be due to mere chance than that a particular order in a pack of cards should result from mechanical shuffling. — Leszek Kolakowski

There is an old saying "well begun is half done" - 'tis a bad one. I would use instead, "Not begun at all till half done;" so according to that I have not begun my Poem and consequently (a priori) can say nothing about it. — John Keats

Mathematically speaking, the probable (that in 6,000,000,000 throws with a regular six-sided die the die will come up proximately 1 ,000,000,000 times) and the improbable (that in six throws with the same die the one will come approximately up six times) are not different in kind, but only in frequency, whereby the more frequent appears a priori more probable.
But the occasional occurrence of the improbable does not imply the intervention of a higher power, something in the nature of a miracle, as the layman is so ready to assume. The term "probability" includes improbability at the extreme limits of probability, and when the improbable does occur this is no cause for surprise, bewilderment or mystification.
Cf. Ernst Mally's Probability and Law, Hans Reichenbach The theory Probability, Whitehead and Russell's Principia Mathematica, von Mises' Probability, Statistics and Truth — Max Frisch

Science asks no questions about the ontological pedigree or a priori character of a theory, but is content to judge it by its performance; and it is thus that a knowledge of nature, having all the certainty which the senses are competent to inspire, has been attained
a knowledge which maintains a strict neutrality toward all philosophical systems and concerns itself not with the genesis or a priori grounds of ideas. — Chauncey Wright

The pragmatist turns away from abstraction and insufficiency, from verbal solutions, from bad a priori reasons, from fixed principles, closed systems, and pretended absolutes and origins. He turns toward concreteness and adequacy, towards facts, towards action, and towards power. — William James

People wonder why there seems to be no meaning in life. Meaning does not exist a priori. There is no meaning existing in life; one has to create it. Only if you create it will you discover it. It has to be invented first. It is not lying there like a rock, it has to be created like a song. It is not a thing, it is significance that you bring through your consciousness. — Rajneesh

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. — John Polkinghorne

Omniscience about life and death is not within a physician's purview. A doctor should never write off a person a priori. — Jerome Groopman

The underground press serves as the only effective counter to a growing power, and more sophisticated techniques used by establishment mass media to falsify, misrepresent, misquote, rule out of consideration as a priori ridiculous, or simply ignore and blot out of existence: data, books, discoveries that they consider prejudicial to establishment interest ... — William S. Burroughs

In fact the a priori reasoning is so entirely satisfactory to me that if the facts won't fit in, why so much the worse for the facts is my feeling. — Erasmus Darwin

I hold that the mark of a genuine idea is that its possibility can be proved, either a priori by conceiving its cause or reason, or a posteriori when experience teaches us that it is in fact in nature. — Gottfried Leibniz

The a priori method is distinguished for its comfortable conclusions. It is the nature of the process to adopt whatever belief weare inclined to, and there are certain flatteries to the vanity of man which we all believe by nature, until we are awakened from our pleasing dream by rough facts. — Charles Sanders Peirce

Physics is to be regarded not so much as the study of something a priori given, but rather as the development of methods of ordering and surveying human experience. In this respect our task must be to account for such experience in a manner independent of individual subjective judgement and therefore objective in the sense that it can be unambiguously communicated in ordinary human language. — Niels Bohr

Imagine being able to plot in advance, in systematic fashion, the approach of all meaningful coincidences. Is that a priori, by the very meaning of the word, not a contradiction? After all, a coincidence, or as Pauli called it, a manifestation of synchronicity, is by its very nature not dependent on the past; hence nothing exists as a harbinger of it (cf. David Hume on the topic; in particular the train whistle versus the train). This state, not knowing what is going to happen next and therefore having no way of controlling it, is the sine qua non of the unhappy world of the schizophrenic; he is helpless, passive, and instead of doing things, he is done to. Reality happens to him
a sort of perpetual auto accident, going on and on without relief. — Philip K. Dick

Intellectually, true beauty is very difficult to distinguish a priori from the bloom of youth. — Andre Breton

All models divide naturally ... into two a priori parts: one is kinematics, whose aim is to parameterize the forms of the states of the process under consideration, and the other is dynamics, describing the evolution in time of these forms. — Rene Thom

Because of the a priori element in intention, good intentions are so tempting - compared with a successive unfolding in time - and have so often in them some narcotic which develops an inner gaze instead of a resilience that begets energy. — Soren Kierkegaard

The pleasure a man gets from a landscape would [not] last long if he were convinced a priori that the forms and colors he sees are just forms and colors, that all structures in which they play a role are purely subjective and have no relation whatsoever to any meaningful order or totality, that they simply and necessarily express nothing ... No walk through the landscape is necessary any longer; and thus the very concept of landscape as experienced by a pedestrian becomes meaningless and arbitrary. Landscape deteriorates altogether into landscaping. — Max Horkheimer

[T]he downside of skepticism: it can easily turn into an arrogant position of a priori rejection of any new phenomenon or idea, a position that is as lacking in critical thinking as the one of the true believer, and that simply does not help either science or the public at large. — Massimo Pigliucci

The question is, how far an opinion is life-furthering, life-preserving, species-preserving, perhaps species-rearing, and we are fundamentally inclined to maintain that the falsest opinions (to which the synthetic judgments a priori belong), are the most indispensable to us, that without a recognition of logical fictions, without a comparison of reality with the purely IMAGINED world of the absolute and immutable, without a constant counterfeiting of the world by means of numbers, man could not live - that the renunciation of false opinions would be a renunciation of life, a negation of life. — Friedrich Nietzsche

A man shouldn't claim to know even himself as he really is by knowing himself through inner sensation - i.e. by introspection. For since he doesn't produce himself (so to speak) or get his concept of himself a priori but only empirically, it is natural that he gets his knowledge of himself through inner sense and consequently only through how his nature appears and how his consciousness is affected. But beyond the character of his own subject, which is made up out of these mere appearances, he necessarily assumes something else underlying it, namely his I as it is in itself. Thus in respect to mere perception and receptivity to sensations he must count himself as belonging to the sensible world; but in respect to whatever pure activity there may be in himself (which reaches his consciousness directly and not by affecting the inner or outer senses) he must count himself as belonging to the intellectual world - though he doesn't know anything more about it. — Immanuel Kant

What we think of as reality is a continuous synthesis of elements from a fixed hierarchy of a priori concepts and the ever changing data of the senses. — Robert M. Pirsig

Self-evidence, of which Russell has said so much, can only be discarded in logic by language itself preventing every logical mistake. That logic is a priori consists in the fact that we cannot think illogically. — Ludwig Wittgenstein

When we use such metaphorically derived inference patterns to reason about morality, the principles we get and use are inextricably tied up with ends, goals, and purposes. In such cases, therefore, the deontological picture of ethical deliberation just doesn't fit.
The deontologist will no doubt respond by insisting that we can keep morality (as a source of moral principles) entirely separate from other domains (such as well-being) whenever we are reasoning about morals. This view entails that learning morality is just learning preexisting patterns of moral reasoning and learning how to apply them to concrete cases.
However, it is important to see that this is an empirical issue about the nature of human reasoning, and it cannot be decided a priori. — George Lakoff

Before anything happens, awareness is already there, a priori. — Osho

It was while I was studying philosophy that I came to understand ... that it is no sign of moral or spiritual strength to believe that for which one has no evidence, neither a priori evidence as in math, nor a posteriori evidence as in science ... It's a violation almost immoral in its transgressiveness to shirk the responsibilities of rationality. — Rebecca Goldstein

We come now to the question: what is a priori certain or necessary, respectively in geometry (doctrine of space) or its foundations? Formerly we thought everything; nowadays we think nothing. Already the distance-concept is logically arbitrary; there need be no things that correspond to it, even approximately. — Albert Einstein

All of life is iterative. It goes back to the point I made earlier, which is you can't a priori know enough to even ask the right questions. — Grady Booch

The so-called law of induction cannot possibly be a law of logic, since it is obviously a proposition with a sense.
Nor, therefore, can it be an a priori law. — Ludwig Wittgenstein

The science of constructing a commonwealth, or renovating it, or reforming it, is, like every other experimental science, not to be taught a priori. Nor is it a short experience that can instruct us in that practical science, because the real effects of moral causes are not always immediate. — Edmund Burke

synthetic judgments a priori should not "be possible" at all; we have no right to them; in our mouths they are nothing but false judgments. — Friedrich Nietzsche

Time is not an empirical concept. For neither co-existence nor succession would be perceived by us, if the representation of time did not exist as a foundation a priori. — Immanuel Kant

If the intuition must conform to the nature of the objects, I do not see how we can know anything of them a priori. If, on the other hand, the object conforms to the nature of our faculty of intuition, I can then easily conceive the possibility of such an a priori knowledge. — Immanuel Kant

God is the great comprehensive a priori integrity of Universe within which human beings find themselves to be operating. — R. Buckminster Fuller

When I tell her about the expression "MILF" ("Mom I'd like to Fuck"), she thinks it's hilarious. There's no French-language equivalent. In France, there's no a priori reason why a woman wouldn't be sexy just because she happens to have children. It's not uncommon to hear a Frenchman say that being a mother gives a woman an appealing air of plentitude (happiness and fulness of spirit). — Pamela Druckerman

Planters clung to their proslavery beliefs even when there were facts to the contrary because the stakes involved in abandoning them were too high. They could not reject or even compromise their central myths, for to do so would mean condemning a whole culture as a lie...Ideologies, once constructed, have lives of their own. Any evidence which might have contradicted the planters' basic beliefs faced an a priori denial. — James L. Roark

Any necessary truth, whether a priori or a posteriori, could not have turned out otherwise. — Saul Kripke

The verdict of a jury is the a priori opinion of that juror who smokes the worst cigars. — H.L. Mencken

Des Grieux was like all Frenchmen, that is, cheerful and amiable when it was necessary and profitable, and insufferably dull when the necessity to be cheerful and amiable ceased. A Frenchman is rarely amiable by nature; he is always amiable as if on command, out of calculation. If, for instance, he sees the necessity of being fantastic, original, out of the ordinary, then his fantasy, being most stupid and unnatural, assembles itself out of a priori accepted and long-trivialized forms. The natural Frenchman consists of a most philistine, petty, ordinary positiveness
in short, the dullest being in the world. In my opinion, only novices, and Russian young ladies in particular, are attracted to Frenchmen. Any decent being will at once notice and refuse to put up with this conventionalism of the pre-established forms of salon amiability, casualness, and gaiety. — Fyodor Dostoyevsky

As so often happens in philosophy, clever people accept a false general principle on a priori grounds and then devote endless labour and ingenuity to explaining away plain facts which obviously conflict with it. — C. D. Broad

Art is a true aesthetic synthesis , "a priori" of feeling and image in the intuition, as to which it may be repeated that feeling without image is blind, and image without feeling is void. — Benedetto Croce

Life has no meaning a priori ... It is up to you to give it a meaning, and value is nothing but the meaning that you choose. — Jean-Paul Sartre

Praxeology is a theoretical and systematic, not a historical, science. Its scope is human action as such, irrespective of all environmental, accidental, and individual circumstances of the concrete acts. Its cognition is purely formal and general without reference to the material content and the particular features of the actual case. It aims at knowledge valid for all instances in which the conditions exactly correspond to those implied in its assumptions and inferences. Its statements and propositions are not derived from experience. They are, like those of logic and mathematics, a priori. They are not subject to verification or falsification on the ground of experience and facts. — Ludwig Von Mises

race has the feel of being a priori, but in reality it is a historical construct that regulates our interhuman relations, though not always toward malicious forms of racism. Indeed, race may also enable forms of community bound by filial care and interests. — Victor Anderson

I am only astonished that, while so many women have intelligent things to say and so many men are still unknown, a publisher cared to print such a little book, and at such a price. That confirms what Schopenhauer reveals to us, among other truths: philosophy is a matter of death. A philosopher living and thinking life is a priori suspect in our philosophical culture. — Luce Irigaray

Her feeling was rather that, given the nature of the human couple, the love of man and woman is a priori inferior to that which can exist (at least in the best instances) in the love between man and dog, that oddity of human history probably unplanned by the Creator. — Anonymous

If time is treated in modern physics as a dimension on a par with the dimensions of space, why should we a priori exclude the possibility that we are pulled as well as pushed along its axis? The future has, after all, as much or as little reality as the past, and there is nothing logically inconceivable in introducing, as a working hypothesis, an element of finality, supplementary to the element of causality, into our equations. It betrays a great lack of imagination to believe that the concept of "purpose" must necessarily be associated with some anthropomorphic deity. — Arthur Koestler

The first part, or the Aesthetics, which has nothing in common with art, disengages the a priori forms of sensible knowledge, namely, the forms of space and time, which furnish mathematics with their object. Aesthetics thus divorced mathematics from reality, for it makes the condition of mathematics not the real, but a mental form of space and time. — Fulton J. Sheen

Nothing can better express the feelings of the scientist towards the great unity of the laws of nature than in Immanuel Kant's words: "Two things fill the mind with ever new and increasing awe: the stars above me and the moral law within me." ... Would he, who did not yet know of the evolution of the world of organisms, be shocked that we consider the moral law within us not as something given, a priori, but as something which has arisen by natural evolution, just like the laws of the heavens? — Konrad Lorenz

[ ... ] there can be no a priori moral framework in a modern democracy [ ... ] — Reza Aslan

Given the complexity of interpersonal relationships and institutions and the complexity of co-ordination of the actions of many people, it is enormously unlikely that, even if there were one ideal pattern for society, it could be arrived at in an a priori fashion. And even supposing that some great genius did come along with a blueprint, who could have the confidence that it could work — Robert Nozick

Here then we see philosophy brought to a critical position, since it has to be firmly fixed, notwithstanding that it has nothing to support it in heaven or earth. Here it must show its purity as absolute director of its own laws, not the herald of those which are whispered to it by an implanted sense or who knows what tutelary nature. Although these may be better than nothing, yet they can never afford principles dictated by reason, which must have their source wholly a priori and thence their commanding authority, expecting everything from the supremacy of the the law and due respect for it, nothing from inclination, or else condemning the man to self-contempt and inward abhorrence. — Immanuel Kant

We must admit with humility that, while number is purely a product of our minds, space has a reality outside our minds, so that we cannot completely prescribe its properties a priori. — Carl Friedrich Gauss

The fact is that people would rather cling when they're afraid of something to a priori beliefs than rather open their minds about it. — Lawrence M. Krauss

4. The falseness of an opinion is not for us any objection to it: it is here, perhaps, that our new language sounds most strangely. The question is, how far an opinion is life-furthering, life- preserving, species-preserving, perhaps species-rearing, and we are fundamentally inclined to maintain that the falsest opinions (to which the synthetic judgments a priori belong), are the most indispensable to us, that without a recognition of logical fictions, without a comparison of reality with the purely IMAGINED world of the absolute and immutable, without a constant counterfeiting of the world by means of numbers, man could not live - that the renunciation of false opinions would be a renunciation of life, a negation of life. TO RECOGNISE UNTRUTH AS A CONDITION OF LIFE; that is certainly to impugn the traditional ideas of value in a dangerous manner, and a philosophy which ventures to do so, has thereby alone placed itself beyond good and evil. — Friedrich Nietzsche

Science and religion both make claims about the fundamental workings of the universe. Although these claims are not a priori incompatible (we could imagine being brought to religious belief through scientific investigation), I will argue that in practice they diverge. If we believe that the methods of science can be used to discriminate between fundamental pictures of reality, we are led to a strictly materialist conception of the universe. While the details of modern cosmology are not a necessary part of this argument, they provide interesting clues as to how an ultimate picture may be constructed. — Sean Carroll

We no longer see the evolution of the nervous system, but that of a certain individual. The role of the memory is very important but ... not as important as we believe. Most of the important things that we do don't depend on memory. To hear, to see, to touch, to feel happiness and pain; these are functions which are independent of memory; it is an a priori thing. Thus, for me, what memory does is to modify that a priori thing, and this it does in a very profound way. — Rodolfo Llinas

What the scientists have always found by physical experiment was an a priori orderliness of nature, or Universe always operating at an elegance level that made the discovering scientist's working hypotheses seem crude by comparison. The discovered reality made the scientists exploratory work seem relatively disorderly. — R. Buckminster Fuller

A priori Logical propositions are such as can be known a priori without study of the actual world. — Bertrand Russell

The judgment that human life is worth living, or rather can and ought to be made worth living, ... underlies all intellectual effort; it is the a priori of social theory, and its rejection (which is perfectly logical) rejects theory itself. — Herbert Marcuse

The prerequisite of contrapuntal art, more conspicuous in the work of Bach than in that of any other composer, is an ability to conceive a priori of melodic identities which when transposed, inverted, made retrograde, or transformed rhythmically will yet exhibit, in conjunction with the original subject matter, some entirely new but completely harmonious profile. — Glenn Gould

Evolutionists ... have a prior commitment, a commitment to naturalism. It is not that the methods and institutions of science somehow compel us to accept a material explanation of the phenomenal world, but, on the contrary, that we are forced by our a priori adherence to material causes to create an apparatus of investigation and a set of concepts that produce material explanations, no matter how counter-intuitive, no matter how mystifying to the uninitiated. Moreover, that materialism is absolute, for we cannot allow a Divine Foot in the door — Richard Lewontin

In this movement of colors I find the essence, which does not arise from a system, or an a priori theory. — Robert Delaunay

The idea of a priori moral judgements ('It is morally wrong to inflict gratuitous pain') is completely acceptable to the vast majority of human beings. Only a few philosophers would disagree. — William Boyd

History is a priori amoral; it has no conscience. — Arthur Koestler

The true function of logic ... as applied to matters of experience ... is analytic rather than constructive; taken a priori, it shows the possibility of hitherto unsuspected alternatives more often than the impossibility of alternatives which seemed prima facie possible. Thus, while it liberates imagination as to what the world may be, it refuses to legislate as to what the world is — Bertrand Russell

My unlucky star had destined me to be born when there was much talk about morality and, at the same time, more murders than in any other period. There is, undoubtedly, some connection between these phenomena. I sometime ask myself whether the connection was a priori, since these babblers are cannibals from the start - or a connection a posteriori, since they inflate themselves with their moralizing to a height which becomes dangerous for others.
However that may be, I was always happy to meet a person who owed his touch of common sense and good manners to his parents and who didn't need big principles. I do not claim more for myself, and I am a man who for an entire lifetime has been moralized at to the right and the left - by teachers and superiors, by policemen and journalists, by Jews and Gentiles, by inhabitants of the Alps, of islands, and the plains, by cut-throats and aristocrats - all of whom looked as if butter wouldn't melt in their mouths. — Ernst Junger

This is a throwback to the Aristotelian conception of nature, banished from the scene at the birth of modern science. But I have been persuaded that the idea of teleological laws is coherent, and quite different from the idea of explanation of the intentions of a purposive being who produces the means to his ends by choice. In spite of the exclusion of teleology from contemporary science, it certainly shouldn't be ruled out a priori. Formally, the possibility of principles of change over time tending toward certain types of outcome is coherent, in a world in which the nonteleological laws are not fully deterministic. — Thomas Nagel

A Critique of pure Reason, i.e. of our faculty of judging a priori according to principles, would be incomplete, if the Judgement, which as a cognitive faculty also makes claim to such principles, were not treated as a particular part of it; although its principles in a system of pure Philosophy need form no particular part between the theoretical and the practical, but can be annexed when needful to one or both as occasion requires. — Immanuel Kant

I largely defer to the cognitive ethologists. I believe that the arguments that they make on this score are extremely persuasive. More than this, I do think as well that a priori objections by philosophers to successful research programs in the sciences have a very bad track record. — Hilary Kornblith

I don't believe in empirical science. I only believe in a priori truth. — Kurt Godel

Most modern physicists have accepted the fact that the role played by the conscious ideas of an observer in every microphysical experiment cannot be eliminated; but they have not concerned themselves with the possibility that the total psychological condition (both conscious and unconscious) of the observer might play a role as well. As Pauli points out, however, we have at least no a priori reasons for rejecting this possibility. But we must loot at this as a still unanswered and an unexplored problem. — C. G. Jung

At one time, many philosophers held that faultless "laws of thought" were somehow inherent, a priori, in the very nature of mind. This belief was twice shaken in the past century; first when Russell and his successors showed how the logic men employ can be defective, and later when Freud and Piaget started to reveal the tortuous ways in which our minds actually develop. — Jean Piaget

In the final analysis, what is it that we call popular, democratic power? Beyond the expressed will of the people, as it is supposedly formulated, there is no appeal; here we meet the absolute, the universal, the indivisible, and the immovable. There is nothing a priori, nothing anterior to democratic power; no ideas of truth, no notions of good or bad, can bind the Popular Will. This 'will' is free in the sense that it stands above all notions of value. It is egalitarian because it is reared on arithmetic equality..It is not open to any appeal, it listens to no demand for grace, no plea for compassion. Like the Sphinx, the Popular Will is immovable in its enigmatic silence. — Tage Lindbom

Whether arrived at through reason or revelation ... natural law is the highest law known to man. It is anchored in the very existential nature of man and is therefore a priori just. — Ilana Mercer

It is possible to demonstrate God's existence, although not a priori, yet a posteriori from some work of His more surely known to us. — Thomas Aquinas

No code of ethics and no effort are justifiable a priori in the face of the cruel mathematics that command our condition. — Albert Camus

So they're the a priori principles of possible experience — Anonymous

And our ages never bothered her from the very beginning. I was married, but that didn't matter, either. She seemed to consider things like age and family and income to be of the same a priori order as shoe size and vocal pitch and the shape of one's fingernails. The sort of thing that thinking about won't change one bit. And that much said, well, she had a point. — Haruki Murakami

Here again, the difference between the effective and the virtual, between mourning and its possibility, seems fragile and porous. The anguished apprehension of mourning (without which the act of friendship would not spring forth in its very energy) insinuates itself a priori and anticipates itself; it haunts and plunges the friend, before mourning, into mourning. This apprehension weeps before the lamentation, it weeps death before death, and this is the very respiration of friendship, the extreme of its possibility. Hence surviving is at once the essence, the origin and the possibility, the condition of possibility of friendship; it is the grieved act of loving. This time of surviving thus gives the time of friendship. — Jacques Derrida

High towers, and metaphysically-great men resembling them, round both of which there is commonly much wind, are not for me. My place is the fruitful bathos, the bottom-land, of experience; and the word transcendental, does not signify something passing beyond all experience, but something that indeed precedes it a priori, but that is intended simply to make cognition of experience possible. — Immanuel Kant

I don't think that anything of any consequence is known a priori: all our knowledge is built up by modifying the lore passed on to us by our ancestors in light of our experiences, and the best a philosopher can do is to learn as much about what has been discovered in various empirical fields, and use it to try to craft an improved synthesis. — Philip Kitcher

One basis for life and another basis for science is a priori a lie. — Karl Marx

The existentialist, on the contrary, finds it extremely embarrassing that God does not exist, for there disappears with Him all possibility of finding values in an intelligible heaven. There can no longer be any good a priori, since there is no infinite and perfect consciousness to think it. It is nowhere written that "the good" exists, that one must be honest or must not lie, since we are now upon the plane where there are only men. Dostoevsky once wrote: "If God did not exist, everything would be permitted"; and that, for existentialism, is the starting point. Everything is indeed permitted if God does not exist, and man is in consequence forlorn, for he cannot find anything to depend upon either within or outside himself. He discovers forthwith, that he is without excuse. — Jean-Paul Sartre

Man feels the urge to run up against the limits of language. Think for example of the astonishment that anything at all exists. This astonishment cannot be expressed in the form of a question, and there is also no answer whatsoever. Anything we might say is a priori bound to be nonsense. Nevertheless we do run up against the limits of language. Kierkegaard too saw that there is this running up against something, and he referred to it in a fairly similar way (as running up against paradox). This running up against the limits of language is ethics. — Ludwig Wittgenstein

I can see no justification whatever for the attitude which refuses on purely a priori grounds to accept action at a distance ... Such an attitude bespeaks an unimaginativeness, a mental obtuseness and obstinacy. — Percy Williams Bridgman

No episode is a priori condemned to remain an episode forever, for every event, no matter how trivial, conceals within itself the possibility of sooner or later becoming the cause of other events and thus changing into a story or an adventure. Episodes are like land mines. The majority of them never explode, but the most unremarkable of them may someday turn into a story that will prove fateful to you. — Milan Kundera

The very hope of experimental philosophy, its expectation of constructing the sciences into a true philosophy of nature, is basedon induction, or, if you please, the a priori presumption, that physical causation is universal; that the constitution of nature is written in its actual manifestations, and needs only to be deciphered by experimental and inductive research; that it is not a latent invisible writing, to be brought out by the magic of mental anticipation or metaphysical mediation. — Chauncey Wright

For morality, with regard to its principles of public right (hence in relation to a political code which can be known a priori), has the peculiar feature that the less it makes its conduct depend upon the end it envisages (whether this be a physical or moral advantage), the more it will in general harmonise with this end. — Immanuel Kant

I am concerned about epistemic normativity, and I don't think that it is just a hangover from a priori and armchair approaches. Some ways of forming beliefs are better than others, and epistemologists of all stripes, I believe, have a legitimate interest in addressing the issue of what makes some of these ways better than others. — Hilary Kornblith

In philosophical terms, the opposite of rationalism is not irrationalism but empiricism, that is, a willingness to form beliefs on the basis of experience rather than from a priori deduction. Empirical evidence never yields the dogmatic certainty that accompanies logical deduction. — John Quiggin

Both a priori reasoning and experience teach us that as as these funds grow larger the geometrical rate of growth by compound interest ultimately defeats itself. — Benjamin Graham

The sensus communis plays no part in Kant - not even in the logical sense. What Kant treats in the transcendental doctrine of judgment - i.e., the doctrine of schematism and the principles - no longer has anything to do with the sensus communis.57 For here we are concerned with concepts that are supposed to refer to their objects a priori, and not with the subsumption of the particular under the universal. — Hans-Georg Gadamer

So long as mathematicians can impose up-and-down semantics upon students while trafficking personally in the non-up-and-down advantages of their concise statements, they can impose upon the
ignorance of man a monopoly of access to accurate processing of information and can fool even themselves by thought habits governing the becoming behavior of professional specialists, by
disclaiming the necessity of, or responsibility for, comprehensive adjustment of the a priori thought to total reality of universal principles. — R. Buckminster Fuller