I have a page dealing with this concept on Doxa, but it's not very good. This is a better version. I will combine the two eventually.
Carl Sagan made this statement popular in its current form, it was originally used by Hume, Laplace and other early theorists, but atheists have sense taken it as a major slogan for their decision-making paradigm.
Marcelo Truzzi tells us:
In his famous 1748 essay Of Miracles, the great skeptic David Hume asserted that "A wise man...proportions his belief to the evidence,"and he said of testimony for extraordinary claims that "the evidence, resulting from the testimony, admits of a diminution, greater or less, in proportion as the fact is more unusual." A similar statement was made by Laplace, and many other later writers. I turned it into the now popular phrase "extraordinary claims require extraordinary proof" (which Carl Sagan popularized into what is almost the war cry of some scoffers).
This slogan allows them to raise the bar for any Christian claim, while lowering it for their own purposes. Ed J. Gracely explains the basic logic of the bromide.
First, it is important to understand that the strength of a conclusion is a function both of the quality of the evidence provided in its support and the a priori probability of the claim being supported. Thus there can never be a single standard of "acceptable evidence" that will suffice to render every claim equally plausible. Suppose, for example, that a reasonably reliable source tells me (a) that President Clinton has vetoed legislation that places restrictions on trade with China and (b) that Newt Gingrich has switched to the Democratic party. Most people would be much more confident of the truth of the first report than of the second, even though the source is identical. The difference lies in the a priori plausibility of the claims.
A more precise formulation requires us to cast the a priori probability of a claim into the form of "odds" in its favor. A proposition with 90% probability of being true has 90 chances of being true for every 10 of being false. Thus the odds are 90 to 10, which reduces to 9 to 1. A proposition with 20% probability of being true has 20 chances of being true for 80 of being false. The odds (in its favor) are 20 to 80 or 0.25 to 1. It is more natural to translate the latter case into odds of 4 to 1 against the proposition, but the calculations require us to work with odds "in favor of" a proposition, even if they are fractional. Pieces of evidence alter the odds in favor of a proposition by a multiplicative factor in proportion to the quality of the evidence.
While it is clear that not all evidence weighs the same, some evidence is better than other evidence, nothing in this explanation indicates why evidence must be stronger for “extraordinary claims” than for “normal claims.” Assuming we can even indicate what “extraordinary evidence” is, what makes it more proven than “ordinary” evidence? The statement above merely indicates that probability is higher for a proposition backed by more direct evidence, nothing more. The rationale says that the least likely proposition is less probable, then the assertion that the evidence must be more “extraordinary” (whatever that means) rather than just accurate or valid or to the point is not demonstrated. Most assumptions about what makes evidence “extraordinary” or “ordinary,” or a proposition likely or unlikely is going to be largely a matter of prejudice. Consider the following statement, also by Gracely:
The principle is clear; the difficulty lies in the application. How likely, for example, is it that homeopathy or therapeutic touch really work? Proponents argue that we need to open our minds to new possibilities and grant these systems a fairly high a priori probability (say, 50-50 odds). Then, even modest-quality evidence would make the claims quite probably true. Skeptics argue that these systems violate known laws of physics and their validity should therefore be considered remotely improbable.
Who decides how likely it is that homeopathy is valid or invalid medicine? One would need a statically average for cure rates to compare with controlled group using orthodox practices to see this. He admits that “modest quality” evidence would be proof if it is granted a high probability. Without the proper studies why not so grant? What if one has found such treatments effective already in one’s own life? This is nothing more than prejudice to judge something improbable on the basis of guesswork and matters of taste. Why shouldn’t a standard of evidence adequate for proof of the issue under consideration, be the issue? I have so far been unable to find an atheist who can tell me what extraordinary God evidence is. I’ve seen attempts on message boards, where they argue absurdities like “why can’t God make all the stars spell out the phrase “burn pain is the worst pain, Jesus is Lord, convert now.” Or God could appear at the UN and hold a press conference. I have yet to see an atheist give me a valid option for “extraordinary evidence.” More importantly, we are talking about God, not about finding Bigfoot. God is off scale for empirical investigation. How can the basis of reality be studied as though just another “thing” in creation? What could be used as a basis of comparison? How could one ever establish a base line comparison to determine probability of God? Dawkns tries it but he merely assumes God would be on a par with any other physical object. What basis is used to establish the probability of something that is said to be beyond our understanding?
An alternative I have heard suggested is to drop the extraordinary proof argument and instead to hold paranormal and alternative medicine claims strictly to the ordinary requirements of replicability and good research. This approach sounds sensible but it has a serious flaw. Skeptics are not willing to accept the plausibility of most paranormal claims unless the evidence is extremely strong. We risk being perceived (correctly) as disingenuous if we call for solid quality research, then revert to the extraordinary claims argument should it in fact appear.(Ibid)
This standard is the one I have been proposing for years. The term he doesn’t use, the proper term for “ordinary” level of proof would be a “prima facie case.” He may have a point if we are talking about acupuncture or UFOs but the flaw he sees in it is attitudinal, not logical or methodological. The attitude of skeptics is out of line anyway. Atheists are not willing to accept any level of evidence. The experience studies are fine studies, they are scientific and a huge body of work backs them up. For all practical purposes, they are “extraordinary evidence.” Let us not forget there is no set standard any skeptic can offer to define that term. Skeptics are quick to brush aside the experience studies as “subjective” without reading the studies or thinking about the arguments. They never define what “extraordinary” evidence would be. Gracely observes that skeptical attitudes are similar even in other areas:
In some areas of paranormal investigation, such as extrasensory perception (ESP), the research is already often better done than much orthodox scientific research, with controls and double-checks most scientists would regard as overkill. Skeptics mostly still feel that the intrinsic implausibility is so great that nothing short of airtight and well-repeated research would be sufficient to support ESP. Little or none of the existing research rises to that level, so we remain skeptical. (Some recent work has been of high quality, see Ray Hyman's article, "The Evidence for Psychic Functioning: Claims vs. Reality", in the March/April 1996 Skeptical Inquirer, pp 24-26.) Had skeptics said some 40 years ago that all we wanted was reasonable quality replicated research, we might now be having to eat our words.
Skeptics are never satisfied. I have seen this problem over and over again. When their demands for evidence are met, they just raise the bar again and again. The tyranny of “extraordinary evidence” so long as one never defines it, allows for this sort of abuse all t he time. More importantly, why should God be subjected to the same standards of proof as empirical objects? Here the skeptic is just in the position of arguing “God is improbable because I don’t believe in him.” Truzzi documents the “catch 22” designed into the extraordinary proof standard:
But it is important to remember that the proponent of the paranormal has an uphill battle from the start. The chips are stacked against him, so his assault is not so threatening to the fabric of science as scoffers often characterize it. In a sense, conservative science has "the law" on its side.
In law, we find three varieties in the weight of burden of proof:
1. proof by preponderance of evidence,
2. clear and convincing proof, and, in criminal law,
3. proof beyond a reasonable doubt.
In conventional science, we usually use (1), but when dealing with extraordinary claims, critics often seem to demand (3) since they demand all alternative explanations must be eliminated before the maverick claim is acceptable. This demand sometimes becomes unreasonable and may even make the scoffer's position unfalsifiable. Since the anomaly proponent is already saddled with a presumption of "guilt," it would seem to me that (2), clear and convincing proof, might be the best standard, though proponents may reasonably wonder why standard (1) should always be denied them.(Ibid)
But we must also keep in mind that God is not “paranormal.” Truzzi and Gracely are speaking in general of any sort of “paranormal” claim, including the claims of alternative medicine. God is not paranormal, but is status quo, normative for human belief. Nor is God a scientific question. It is absurd to expect us to limit evidence to only the scientific when the question about belief is epistemological. More on this aspect of belief and it is import for evidential standards below. But this does raise a further question about the extraordinary evidential standard:
In addition to defining the term “extraordinary evidence” there is also a need to define the term “extraordinary claim.” Why is God an extraordinary claim? Here the atheist is truly in the position of arguing “God is improbable because I don’t believe in him.” Atheists make up 3% of the world’s population at best. The overwhelming majorities of people alive today, or who have ever lived, believe in some form of God. Our brains are hard wired to have thoughts of God. Our physical and mental health work better when we believe in God (as will be seen in latter chapters). Obviously we are fit for belief, why would belief be extraordinary? Why should we allow the minor little 3% minority to define what is normative for humanity? Belief in God is is far more than just the average belief; it is normative as a standard of human understanding. It forms the basis of our psyches, it forms the basis of our legal system; it is the chief metaphor regulating meaning and morality. Belief in God illustrates all the aspects of a prima facie case. This is at least so for RE. Marcelo Truzzi makes the same point:
The central problem however lies in the fact that "extraordinary" must be relative to some things "ordinary." and as our theories change, what was once extraordinary may become ordinary (best seen in now accepted quantum effects that earlier were viewed as "impossible"). Many now extraordinary claims may become more acceptable not when they are replicated but when theoretical contexts change to make them more welcome.(Ibid)
Skeptics have argued that religious experience is not regular or consistent because such experiences are all different. Not only do you have so many different religions, but also even from mystic to mystic things differ. Over the years as one develops a disciplined life of prayer, one does encounter growing diversity and newness, but a certain sense of the familiar as well. Experiences become regular and consistent in that the presence of God is usually found in prayer, the sense of the presence is always the of the same quality (although varying intensity) and the sense of God can become familiar enough that it is always recognized as the same, This sense of the familiar is communicable and can be recognized form one believer to another. The mystical and devotional literature presents a kind of ordered sameness. One can read accounts as different form one experiencer to another as those between St. Augustine and A.W. Tozer and still find passages that seem to be talking about the same things. This is amplified times millions of believers in the history of the church who have experienced the same things. Even though there is diversification and difference there is still sameness. This is not even confined to mystics. The same can be said of conversion accounts that the same aspects keep popping up. Once can recognize the work of God from one person to another, form one time to the next, from one culture to all cultures. But, the skeptic will ask, what about the vast array of different religions? These differences are due to cultural constructs. One experiences God beyond words, and when one tries to speak of such experiences one must encode them in a symbolic universe, that is to say, in culture. These differences in symbolic universes over time have spelled out the differences in the many religions. But there is a cretin unity even between all the differences in religion. The data presented long term effects of religious experience (see articles on RE in this blog) represents typologies, which can be used to compare "peak experience" with that of other phenomena. The Peak experiencers can be grouped together into a collection of those who have experiences X. They are not isolated assortments of differing phenomena. These studies do represent differing cultures and times. Thus, religious experience has a consistency to it even between cultures.
Archetypal symbology universal.
Religions, Values, and Peak-Experiences. Abraham H. Maslow
Appendix I. An Example of B-Analysis
"...Jungian archetypes which can be recovered in several ways. I have managed to get it in good introspects simply by asking them directly to free associate to a particular symbol. The psychoanalytic literature, of course, has many such reports. Practically every deep case history will report such symbolic, archaic ways of viewing the woman, both in her good aspects and her bad aspects. (Both the Jungians and the Kleinians recognize the great and good mother and the witch mother as basic archetypes.) Another way of getting at this is in terms of the artificial dream that is suggested under hypnosis. It can also probably be investigated by spontaneous drawings, as the art therapists have pointed out. Still another possibility is the George Klein technique of two cards very rapidly succeeding each other so that symbolism can be studied. Any person who has been psychoanalyzed can fairly easily fall into such symbolic or metaphorical thinking in his dreams or free associations or fantasies or reveries.
Archetypal Symbology linked to Peak experience.
The link from Archetypes to religious experience is supplied by Maslow as well, in a quotation already sited in Religious Experience Arguments. He argues that the ability to relate "B knowlege" to "C knowlege" where the female (Or the male) is blanced in the perception of the other between goddess and whore, and the proper ego relation is sorted out, is the managing of the sacred and profane. He points out that anyone can learn to see in this manner and that it is indicative of permeative people in their religious experiences as they explained the world through the sense of the numenous.
d) Anyone can have peack expirence --universal to humanity
Religions, Values, and Peak-Experiences
Abraham H. Maslow
Appendix D. What is the Validity of Knowledge Gained in Peak-Experiences?
"To summarize, the major changes in the status of the problem of the validity of B-knowledge, or illumination-knowledge, are: (A) shifting it away from the question of the reality of angels, etc., i.e., naturalizing the question; (B) affirming experientially valid knowledge, the intrinsic validity of the enlarging of consciousness, i.e., of a wider range of experiencing; (C) realizing that the knowledge revealed was there all the time, ready to be perceived, if only the perceiver were "up to it," ready for it. This is a change in perspicuity, in the efficiency of the perceiver, in his spectacles, so to speak, not a change in the nature of reality or the invention of a new piece of reality which wasn't there before. The word "psychedelic" (consciousness-expanding) may be used here. Finally, (D) this kind of knowledge can be achieved in other ways; we need not rely solely on peak-experiences or peak-producing drugs for its attainment. There are more sober and laborious—and perhaps, therefore, better in some ways in the long run—avenues to achieving transcendent knowledge (B-knowledge). That is, I think we shall handle the problem better if we stress ontology and epistemology rather than the triggers and the stimuli."
2) Why Does God seem Hidden to SO many people?
a) God is not strictly speaking "invisable."
According to Hartshorne, "[o]nly God can be so universally important that no subject can ever wholly fail or ever have failed to be aware of him (in however dim or unreflective fashion)." Now the issue of why God doesn't hold a "press conference" has do do with the fact that God does not communicate by violating normal causal principles. In process terms, the "communication" of God must be understood as the prehension of God by human beings. A "prehension" is the response of an occasion to the entire past world (both the contiguous past and the remote past.) As God is in every occasion's past actual world, every occasion must "prehend" or take account of God.
It should be noted that "prehension" is a generic mode of perception that does not necessarily entail consciousness or sensory experience. In previous postings I explained that there a two modes of pure perception --"perception in the mode of causal efficacy" and "perception in the mode of presentational immediacy." If God is present to us, then it is in the presensory perceptual mode of causal efficacy as opposed to the sensory and conscious perceptual mode of presentational immediacy. That is why God is "invisible", i.e. invisible to sense perception. The foundation for experience of God lies in the nonsesnory nonconscious mode of prehension. So now, there is the further question: Why is there variability in our experience of God?. Or, why are some of us atheists, pantheists, theists, etc.? Every prehension has an initial datum derived from God, yet there are a multiplicity of ways in which this datum is prehended from diverse perspectives.
I agreed with Hume that sense perception tells us nothing about efficient causation (or final causation for that matter). Hume was actually presupposing causal efficacy in his attempt to deny it (i.e., in his relating of sense impressions to awareness). Causation could be described as an element of experience, but as Whitehead explains, this experience is not sensory experience. From Hume's own analysis Whitehead derives at least two forms of nonsensory perception: the perception of our own body and the nonsensory perception of one's past.
b). Atheists basically deny the validity of religious experience because they assume that all perception is sense perception.
Or, they deny sense perception to theists when they actually presuppose it themselves (Hume is a case in point).
c) All people experience the reality of God or the "Holy" all the time.
But this is at an unconscious level. However, in some people, this direct prehension of the "Holy" rises to the level of conscious experience. We generally call theses people "mystics". Now, the reason why a few people are conscious of God is not the result of God violating causal principle; some people are just able to conform to God's initial datum in greater degree than other people can. I don't think that God chooses to make himself consciously known to some and not to others. That would make God an elitist. Now, the question as to why I am a theist as opposed to an atheist does not have to do with me experiencing some exceptional religious or mystical experience. Rather, I believe that these extraordinary experiences of the great religious leaders are genuine and that they do conform to the ultimate nature of things. It's not necessarily a "blind leap" of faith, as my religious beliefs are accepted, in part, on the basis of whether or not they illuminate my experience of reality.
The upshot of all of this is religious belief is normative for human behavior. It is not merely "normal" but "normative" meaning it sets the standard. Belief is basic to human psyche, to our understanding of the good, of meaning in life, the ultiamte limits of reality, the grounding of nature and being itself, there is no way belie in God can be thought of as an extraordinary claim! We might think of it as extraordinary in the the sense of being unique, like no other claim, but in that case it makes no sense to subject it to the regular canons of science as though God's presence is given in daily empirical data. Obviously the more intelligent evidential standard is that the evidence has to be fit for the claim. Fit, not dazzling, not impossible, not amazing, no beyond our ability to produce, but it has to fit the case. It has to be rational, and able to stand a prima facie burden, and it has to fit the proof attempted.
Marcelo Truzzi “on some unfair practices toward claims of the Paranormal.” This article was published in slightly edited form in:Edward Binkowski, editor, Oxymoron: Annual Thematic Anthology of the Arts and Sciences, Vol.2: The Fringe, New York: Oxymoron Media, Inc., 1998. It is also found on the website Skeptical Investigations: http://www.skepticalinvestigations.org/anomalistics/practices.htm visited 7/7/08
Ed J. Gracely ”Why Extraordinary Claims Demand Extraordinary Proof. This article first appeared in the December 1998 issue of Phactum, the newsletter of the Philadelphia Association for Critical Thinking (PhACT). Dr. Gracely is Associate Professor of Community and Preventive Medicine at the MCP*Hahnemann School of Medicine in Philadelphia. This article was posted on July 24, 2003. It is now found on:Quackwatch http://www.quackwatch.org/01QuackeryRelatedTopics/extraproof.html
Abraham MaslowReligious Values and peak Experience,
text online: http://www.druglibrary.org/schaffer/lsd/maslow.htm
url for my RE argument: http://www.doxa.ws/experience/mystical.html