Carl Sagan Quotes…

Absence of evidence is not evidence of absence. – Carl Sagan.

If you want to make an apple pie from scratch, you must first create the universe. – Carl Sagan.

If we long to believe that the stars rise and set for us, that we are the reason there is a Universe, does science do us a disservice in deflating our conceits? – Carl Sagan.

Science is not only compatible with spirituality; it is a profound source of spirituality. – Carl Sagan.

Skeptical scrutiny is the means, in both science and religion, by which deep insights can be winnowed from deep nonsense. – Carl Sagan.

“It seems to me what is called for is an exquisite balance between two conflicting needs: the most skeptical scrutiny of all hypotheses that are served up to us and at the same time a great openness to new ideas . . . If you are only skeptical, then no new ideas make it through to you . . . On the other hand, if you are open to the point of gullibility and have not an ounce of skeptical sense in you, then you cannot distinguish the useful ideas from the worthless ones.”
—”The Burden of Skepticism,” -Carl Sagan, The Skeptical Inquirer, 1987

…star stuff, contemplating star stuff… – Carl Sagan, …on humankind…

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~ by revolutionwithin on April 2, 2009.

8 Responses to “Carl Sagan Quotes…”

  1. Carl Sagan was of course one of the foremost scientists of the 20th century and one of its most admired minds. The first is not an original quote per se, it is more like a repeat of a popular belief in law, that absence of evidence is not evidence of absence. One cannot but agree with the fourth quote here – his observation that science the most spiritual of endeavours. The fact that we can bring the power of reason to the method by which we explain the goings on in this world is a comforting thought. It encourages elevated and honest thinking and action in those who sincerely practice it. However, for those of us who don’t use exactly the method of reason, it is possible to say that a body of ethics, such as in a religion, will have a good effect. Humans have evolved to ignore reason in times when they are under threat or are otherwise overwhelmed, so practiced habits and instinct take over at these times.

  2. Carl Sagan explicitly criticized the maxim (which has been attributed to cosmologist Martin Rees) “Absence of evidence is not evidence of absence.” as an argument from ignorance:

    “appeal to ignorance — the claim that whatever has not been proved false must be true, and vice versa (e.g. There is no compelling evidence that UFOs are not visiting the Earth; therefore UFOs exist — and there is intelligent life elsewhere in the universe. Or: There may be seventy kazillion other worlds, but not one is known to have the moral advancement of the Earth, so we’re still central to the Universe.) This impatience with ambiguity can be criticized in the phrase: absence of evidence is not evidence of absence.”

    Reducing that last sentence to “Absence of evidence is not evidence of absence.” is a quote mine. The rest of that very sentence is clearly arguing against that statement.

  3. I have become more concerned in the last decade with WHAT is being said rather than WHO is saying it.

    “Absence of evidence is not evidence of absence”, if you look at it simply in terms of what is being said, there is no inference that what has not been proved must be true.

    The absence of evidence for God, for instance, does not prove the existence of God, BUT… it does not disprove him either.

    And in that, it is an entirely lucid piece of logic. This kind of openness to exploring that which YET has not been proved is required. I believe Abraham Maslow made similar statements in his critique of science. His article on Humanistic Science and Transcendent Experiences is strikingly thoughtful.

    • Don’t conflate evidence with proof, vajra.

      “Absence of evidence is not proof of absence.” is a true statement.
      “Absence of evidence is not evidence of absence.” is a false statement.

  4. I am not interchanging proof and evidence here.

    Within this statement:
    “Absence of evidence is not evidence of absence.”

    The second use of the word “evidence” is as to mean “self-evident.” That the absence of evidence (for a particular idea or thing) does not in and of itself make it self-evident that the thing does not exist.

    You are confusing yourself too much in being pedantic. This is called missing the forest for the trees.

    I suggest you learn to grok – check Robert Heinlein’s “Stranger in a Strange Land” to understand grokking.

    Cheers.

  5. I am not interchanging proof and evidence here.

    Oh? Seemed like you did three times in your previous post.

    The second use of the word “evidence” is as to mean “self-evident.” That the absence of evidence (for a particular idea or thing) does not in and of itself make it self-evident that the thing does not exist.

    Even in your oddly phrased restatement, that statement is untrue. For example: Looking under your bed and finding an absence of evidence of a monster makes it self-evident that the monster under your bed does not exist.

    You are confusing yourself too much in being pedantic. This is called missing the forest for the trees.

    You’re rather condescending.

    No confusion here. Maybe it’s on your end.

    I suggest you learn to grok – check Robert Heinlein’s “Stranger in a Strange Land” to understand grokking.

    I’ve read it, water brother. So you suggest I merge with the expression, blend into the expression, lose identity in the expression, be the expression. Ommmm.

    Then perhaps I should learn Martian and practice telekinesis.

  6. Oh? Seemed like you did three times in your previous post.

    It was a response to the terms used in your post. Again, keep things in context, water brother. It was Carl Sagan who had conflated evidence with proof, not I. If you read my response, I was saying it DOES NOT PROVE.

    I am not being condescending here, rather being straightforward. You really are missing the forest for the trees in your tendency to be overly superficial. Even with such a superficial understanding of grokking. This kind of superficiality, this lack of consideration, is the real condescending attitude.

    For example: Looking under your bed and finding an absence of evidence of a monster makes it self-evident that the monster under your bed does not exist.

    No it does not. All it does is make it self-evident that you did not find a monster under the bed – it speaks nothing for its existence. In assuming that lack of evidence is proof is where we often conflate evidence with proof, as you did with the monster under the bed analogy.

    But even before stepping to making statements that such and such evidence proves such and such hypothesis – you are missing the point here, and I will ask you one final time to actually consider it, instead of arguing with me for the sake of argument:

    The fact that you did not “detect” something could be because our MANNER of investigating it was FLAWED to begin with.

    That is the proposition of the statement – “absence of evidence is not evidence of absence.”

    It does not necessarily mean that the monster under the bed actually exists – the statement does not validate its existence, and this is where Carl Sagan, and you, have become confused. The statement refers to the fundamentals of good science – that is for example; until the atom was investigated in a MANNER that was sufficient to reveal that the atom was mostly empty, it was assumed that the atom was a full ball of mass.

    Or in other terms;

    “Strictly speaking, no hypothesis or theory can ever be proven. It can only be disproven. When we say we believe in a theory, what we really mean is that we are unable to show that the theory is wrong – not that we are able to show, beyond doubt, that the theory is right.” – Gerhard Robbins, Physicist.

    Robbins makes this statement because of the ever-looming conundrum in science that our conclusions largely depend on the manner in which we investigate; which can always be flawed, or even partially flawed to begin with.

    “Absence of evidence is not evidence of absence” is a literary use of context and subtext, which I appreciate. The quote invokes two meanings of the word “absence”. In its first use, “absence” refers to a “lack of”, the second refers to “existence.” – Lack of evidence is not evidence of no-existence.

    Lack of evidence to prove a man committed a murder does not IN AND OF ITSELF mean he did not commit it. It simply means there is lack of evidence for it. (Yet because we work under evidence, many criminals walk because they destroy evidence and many innocents are jailed because of false evidence).

    At the time when Einstein was coining the theory of relativity, it was based on a logical thought experiment – yet in the popular science of that time his conclusions were seen to contradict their “current” evidence. Yet the absence of evidence, in that case, was not evidence of the invalidity of Einstein’s conclusions.

    The author of the phrase has invoked evidence twice (instead of using proof), with definite purpose. Because the author realizes that people are often conflating evidence and proof – that lack of evidence, to them, is proof of non-existence. To point out this not merely scientific, but social dilemma, he uses evidence twice. To make those ready to really think, consider what they have otherwise taken for granted. The phrase essentially means; be open minded – as your evidence in itself depends on the limitations of your own perspective. The task here is to widen one’s horizon of understanding, to be honest with yourself and acknowledge what exactly it is you know for a fact! The more honest among us soon realize that all they really know is that they exist – but nothing further than that.

    Take a read of Abraham Maslow’s “Humanistic Science and Trancedental Experiences.” And frankly, this time, don’t read it superficially.

    https://vajrakrishna.wordpress.com/2009/05/04/humanistic-science-and-trancendent-experiences/

    To grok means to UNDERSTAND IN FULLNESS – where it becomes less of a perspective, and more of a peak experience.

  7. The Sagan quote from the Demon-Haunted World relates to the nature of humans being impatient with ambiguity, of not having a definite yes or definite no and being “content” with simply saying “I do not know.” Thus, Sagan says, “This impatience with ambiguity can be criticized in the phrase: absence of evidence is not evidence of absence.” Perhaps Sagan could have worded the above as “This impatience with ambiguity or not knowing for sure is evidenced by the phrase: the absence of evidence is not evidence of absence.”

    There is another quote that is pertinent to all of the above arguments:
    “Evidence without context is ambiguous at best.” You may find the source of this brings a smile to your face; it is “CSI-Crime Scene Investigation” from 12/12/05.

    Stephen Strum

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