I will quote here, at length, various passages from The Demon-Haunted World bearing on the definition and value of bona fide science. Sagan so often said it so very well:
Superstition and pseudoscience keep getting in the way, distracting [believers in pseudoscience], providing easy answers, dodging skeptical scrutiny, casually pressing our awe buttons and cheapening the experience, making us routine and comfortable practitioners as well as victims of credulity. Yes, the world would be a more interesting place if there were UFOs lurking in the deep waters off Bermuda and eating ships and planes, or if dead people could take control of our hands and writers messages. It would be fascinating if adolescents were able to make telephone handsets rocket off their cradles just by thinking at them or if our dreams could, more often than can be explained by chance and our knowledge of the world, actually foretell the future. These are all instances of pseudoscience. They purport to use the methods and findings of science, while in fact they are faithless to its nature-often because they are based on insufficient evidence or because they ignore clues that point the other way. They ripple with gullibility. (Page 13)
Pseudoscience is easier to contrive than science, because distracting confrontations with reality–where we cannot control the outcome of the comparison–are more readily avoided. The standards of argument, what passes for evidence, are much more relaxed. In part for the same reasons, it is much easier to present pseudoscience to the general public than science.
At the heart of some pseudoscience (and some religion also, new age and old) is the idea that wishing makes it so. How satisfying it would be, as in folklore and children’s stories, to fulfill our hearts desire just by wishing. How seductive this notion is, especially when compared with the hard work and good luck usually required to achieve our hopes. (Page 14)
Religions are often the state-protected nurseries of pseudoscience, although there is no reason why religions have to play that role. Anyway, it’s an artifact from times long gone. (Page 15)
Pseudoscience differs from erroneous science. Science thrives on errors, cutting them away one by one. False conclusions are drawn all the time, but they are drawn tentatively. Hypotheses are framed so they are capable of being disproved. A succession of alternative hypotheses is confronted by experiment and observation. Science gropes and staggers toward improved understanding. Proprietary feelings are of course offended when a scientific hypothesis is disproved, but such disproofs are recognized as central to the scientific enterprise. Pseudoscience is just the opposite. Hypotheses are often framed precisely so they are invulnerable to any experiment that offers a prospect of disproof, so even in principle they cannot be invalidated. Practitioners are defensive and wary. Skeptical scrutiny is opposed. When the pseudoscientific hypothesis fails to catch fire with scientists, conspiracies to suppress it are deduced. (21)
It is a supreme challenge for the popularizer of science to make clear the actual, tortuous history of its great discoveries and the misapprehensions and occasional stubborn refusal by its practitioners to change course. Many, perhaps most, science textbooks for budding scientists tread lightly here. It is enormously easier to present in an appealing way the wisdom distilled from centuries of patient and collective interrogation of nature than to detail the messy distillation apparatus. The method of science, as stodgy and grumpy as it may seem, is far more important than the findings of science. (Page 22)
Science is more than a body of knowledge; it is a way of thinking. (Page 25).
The scientific way of thinking is at once imaginative and disciplined. This is central to its success. (Page 27).
One of the reasons for its success is that science has built-in, error correcting machinery at its very heart. Some may consider this an overbroad characterization, but to me every time we exercise self-criticism, every time we test our ideas against the outside world, we are doing science. When we are self indulgent and uncritical, when we confuse hopes and facts, we slide into pseudoscience and superstition. (Page 27)
Humans may crave absolute certainty; they may aspire to it; they may pretend, as partisans of certain religions do, to have attained it. But the history of science–by far the most successful claim to knowledge accessible to humans–teaches that the most we can hope for is the success of improvement in our understanding, learning from our mistakes, and asymptotic approach to the universe, but with the proviso that absolute certainty will always be lewd us. (Page 28).
One of the great Commandments of science is, “mistrust arguments from authority.” (Scientists, being primates, and thus given to dominance hierarchies, of course do not always follow this commandment.” (Page 28).
Because science carries us toward an understanding of how the world is, rather than how we would wish it to be, its findings may not in all cases be immediately comprehensible or satisfying. It may take a little work to restructure our mindsets. (Page 29).
“Spirit” comes from the Latin word “to breathe.” What we breathe is air, which is certainly matter, however thin. Despite usage to the contrary, there is no necessary implication in the word “spiritual” that we are talking of anything other than matter (including the matter of which the brain is made), or anything outside the realm of science. On occasion, I will feel free to use the word. Science is not only compatible with spirituality; it is a profound source of spirituality. When we recognize our place in an immensity of light years and in the passage of ages, only grasp the intricacies, beauty and subtlety of life, then that soaring feeling, that sense of the relation and humility combined, is surely spiritual. (Page 29).
[More of Sagan’s quotes under the fold]
Not every branch of science can foretell the future–paleontology can’t–but many can and with stunning accuracy. (Page 30).
If you want real accuracy (here, 99% accuracy), try amniocentesis and sonograms. Try science. Think of how many religions attempt to validate themselves with prophecy. … There isn’t a religion on the planet that doesn’t long for a comparable ability–precise, and repeatedly demonstrated before committed skeptics–to foretell future events. No other human institution comes close. Is this worshiping at the altar of science? Is this replacing one faith by another, equally arbitrary? In my view, not at all. The directly observed success of science is the reason I advocate its use. If something else worked better, I would advocate the something else. (Page 30).
Again, the reason science works so well is partly that built-in error correcting machinery. There were no forbidden questions in science, no matter stay sensitive or delicate to be probed, no sacred truths. That openness to new ideas, combined with the most rigorous, skeptical scrutiny of all ideas, since the wheat from the chaff. It makes no difference how smart, august, or beloved you are. You must prove your case in the face of determined, expert criticism. Diversity and debate are valued. Opinions are encouraged to contend–substantively and in-depth. (Page 31).
Some people consider science arrogant-especially when it purports to contradict beliefs of long-standing or when it introduces bizarre concepts that seem contradictory to common sense. I can earthquake that rattled our faith in the very ground were standing on, challenging our accustomed beliefs, shaking the doctrines we have grown to rely upon can be profoundly disturbing. Nevertheless, I maintain that science is part and parcel humility. Scientists do not seek to impose their needs and wants on nature, but instead humbly interrogate nature and take seriously what they find.We are aware that revered scientists have been wrong. We understand human imperfection. We insist on independent and-to the extent possible-quantitative verification of proposed tenets of belief. We are constantly prodding, challenging, seeking contradictions or small, persistent residual errors, proposing alternative explanations, encouraging heresy. We give our highest rewards to those who convincingly disprove established beliefs. (Page 33).
Which leaders of the major faiths acknowledge that their beliefs might be incomplete or erroneous and established institutes to uncover possible doctrinal deficiencies? Beyond the test of everyday living, who is systematically testing the circumstances in which traditional religious teachings may no longer apply? (Page 34).
Science, Anne Druyan notes, is forever whispering in our ears, “Remember, you’re very new at this. You might be mistaken. You been wrong before.” . . . No contemporary religion and no new age belief seems to me to take sufficient account of the grandeur, magnificence, subtly and intricacy of the universe revealed by science. The fact that so little of the findings of modern science is prefigured in Scripture to my mind casts further doubt on its divine inspiration. But of course I might be wrong. (Page 35).
[Compare the above with this article by Sagan]
Children need hands-on experience with the experimental method rather than just reading about science in a book. We can be told about oxidation of wax as an explanation of the candle flame. But we have a much more vivid sense of what’s going on if we witness the candle burning briefly in a bell jar until the carbon dioxide produced by the burning surrounds the wick, blocks access to oxygen, and the flame flickers and dies. We could be taught about mitochondria in cells, how they mediate the oxidation of food like the flame burning the wax, but it’s another thing altogether to see them under the microscope. (p. 326).
dangerousintersection.org/2009/01/11/science-versus-pseudoscience-according-to-carl-sagan/