10 Dinge, die wir vor der wissenschaftlichen Methode für wahr hielten

Fragen Sie die Wissenschaft nach einigen ihrer peinlicheren Momente, und sie wird Sie wahrscheinlich mit einem Vortrag darüber langweilen, wie sie sich früher ganz auf Logik und Deduktion konzentrierte (ein Top-down-Ansatz, der spezifische Fälle aus allgemeinen Prinzipien ableitet), aber dann gereift und gereift ist in die Induktion (ein Bottom-up-Ansatz, der aus vielen Beobachtungen breite Schlussfolgerungen zieht).

Natürlich wird die Wissenschaft herunterspielen, wie lang und peinlich diese Jugend tatsächlich war. Sein Spiel mit der Es-ist-so-falsch-aber-fühlt-sich-so-richtig-Naturphilosophie von Aristoteles überdauerte das Mittelalter um Jahrhunderte. Tatsächlich hat die Wissenschaft ihre (buchstäblichen) Dämonen nicht wirklich erschüttert, bis im 16. Jahrhundert eine Intervention von Galileo , der sie mit einigen erschütternden Beobachtungen traf, und von Francis Bacon, der sie dazu brachte, sich selbst genau zu betrachten. Danach zog die Wissenschaft aus dem Keller ihrer Eltern aus, packte ihre Astrologieplakate ein und bekam einen 9-to-5-Job, der evidenzbasierte Untersuchungen durch Beobachtungen, Hypothesen, Datensammlung, Experimente und Tests durchführte, auch bekannt als die wissenschaftliche Methode .

Aber es hatte einige großartige Geschichten zu erzählen.

1. Körperliche Säfte
2. Kosmische Hüllen umgeben die Erde
3. Ein zentrales Feuer, eine Gegenerde und ein paar Epizyklen
4. Alle Materie besteht aus Wasser ... oder ist es Luft?
5. Spontane Generation
6. Miasma-Theorie
7. Mütterlicher Eindruck
8. Blut wird herauskommen ... Irgendwann
9. Aristoteles' Interpretation der Physik
10. Aderlass als legitimes medizinisches Heilmittel

Ohne eine angemessene Methodik kann Sie allein die Vernunft in viele Sackgassen führen, daher ist es nicht verwunderlich, dass der Vater der westlichen Medizin auch seinen Anteil an Quacksalber-Ideen hervorgebracht hat.

Zum Beispiel suchte Hippokrates nach natürlichen Ursachen für angeblich übernatürliche Leiden, einschließlich der „heiligen Krankheit“ der Epilepsie – damals als Beweis für die Besessenheit durch Götter oder Dämonen angesehen . Er war auch Pionier der verqueren Vorstellung von Körperflüssigkeiten oder Körpersäften , von denen er sagte, dass sie die menschliche Gesundheit, das Aussehen und die Disposition bestimmen. Die medizinische Praxis, die auf dem Ausgleich von Blut, Schleim, Galle (auch Choler genannt) und schwarzer Galle (alias Melancholie) basierte, die angeblich jeweils von einem anderen Organ reguliert wurden, hielt bis Mitte des 17. Jahrhunderts an. Sein Vermächtnis lebt in Wörtern wie sanguinisch (lat. sanguineus „aus Blut“, was optimistisch oder positiv bedeutet) und melancholisch (deprimiert) weiter [Quellen: Encyclopaedia Britannica ; NLM].

Ärzte versuchten, die Körpersäfte durch Ernährung und Bewegung zu regulieren und indem sie körperliche Ausscheidungen wie Urin untersuchten. So weit, ist es gut. Das Problem war, dass sie jede Krankheit auf diese Ursachen zurückführten und die Wurzeln schmerzhafter und tödlicher Störungen jahrhundertelang misshandelten oder ignorierten. In der Tat, weit davon entfernt, die fehlerhaften Flüssigkeiten aufzugeben, verdoppelten die Praktizierenden sie und verbanden nach und nach Säfte mit Eigenschaften (nass/trocken, heiß/kalt), Elementen (Erde, Luft, Feuer und Wasser), Jahreszeiten und Lebensabschnitten. Ähnliche Ideen bestehen heute im indischen Ayurveda und in der traditionellen chinesischen Medizin [Quellen: NLM ; Wissenschaftsmuseum (Großbritannien) ].

Antike griechische Astronomen, die sich mit den verschiedenen Zickzacks, Zacks und Neigungen himmlischer Bewegungen auseinandersetzen, haben einige neuartige Erklärungen entwickelt. Einige von ihnen kreisten sogar nahe der Wahrheit. Wie die Sumerer vor ihm bemerkte Anaximenes im 6. Jahrhundert v. Chr., dass Planeten alleine über den Sternenhintergrund wanderten. Aber er schloss die Sterne auch in eine starre, ewige Sphäre ein, von der er sagte, dass sie sich um die Erde drehte, eine Idee, die den Geozentrismus überdauern und bestehen bleiben würde, bis Edmund Halley 1718 die souveräne Bewegung der Sterne beobachtete [Quellen: Belen et al. ; Brandt ; Graham ; Kanas ].

Als weitere Beobachtungen das Modell belasteten, fügten alte Astronomen immer wieder Muscheln hinzu. Sie steckten Sterne in Muscheln, Planeten in Muscheln – sie schnappten sogar Sonne und Mond aus ihrer freischwebenden Heimat in der Luft und steckten sie in Muscheln. Einige sagten, die Sterne, die Sonne und der Mond seien nur Löcher in einem kolossalen kosmischen Sieb, das das heilige Feuer dahinter offenbarte. Wenn diese Löcher blockiert waren, erzeugten sie Mondphasen und Finsternisse [Quellen: Graham ; Allen ; Kanas ].

Diese Anhäufung von Sphären gipfelte in charmanten und lächerlich komplexen Systemen, die von Eudoxus im vierten Jahrhundert v. Chr. erfunden wurden und bis zu 27 verschachtelte und verbundene Sphären umfassten, von denen sich jede um ihre eigene Achse drehte und die anderen beeinflusste [Quellen: Allen ; Kanas]. Eudoxus hätte mehr erfunden, aber William of Occam reiste in der Zeit zurück und hackte ihn mit einem Rasiermesser.

Diese alten Griechen glaubten auch, dass die Erde ungefähr zwei Jahrtausende alt war, bevor Kolumbus oder Magellan segelten. Einige argumentierten auch gegen Geozentrismus – nur nicht immer aus den richtigen Gründen.

Take the Pythagoreans, the semimystical group founded by famed mathematician Pythagoras in sixth century B.C.E. that removed Earth from the center of the universe for various reasons. To them, Earth circled a Central Fire, as did the sun, moon, planets, stars and a made-up counter-Earth (aka antichthon). At the time, setting the Earth in motion represented a radical shift in thought, but then the Pythagoreans -- who avoided beans, picking up fallen objects or touching white roosters -- waltzed to their own tune: the music of the spheres [sources: Allen; Burnet ; Lewis and Chasles ; Toulmin and Goodfield ].

If anything, attempts to salvage geocentrism in light of contrary observations were just as wacky and far more byzantine. Mercury and Venus, whose travels appeared tangled with the sun's, were moved inward or set in orbits around it, even as it orbited us. In the second century, Claudius Ptolemy explained retrograde motion, the apparent backing and looping of planets caused by differing orbital speeds, by resorting to orbits-within-orbits called epicycles. This Aristotelian-Ptolemaic cosmology dominated until Nicolaus Copernicus put the sun back in the center where it belonged, and Galileo proved him right [sources: Encyclopaedia Britannica; Gagarin and Cohen ; Toulmin and Goodfield ; Yost and Daunt].

To early Greek philosophers, all matter was made of a single substance, even if they couldn't agree what it was. For astronomer and geometrician Thales, it was water; for Anaximenes, it was air (both lived in sixth century B.C.E.). Far from arbitrary, these choices stemmed from observations of changing states of matter. Anaximenes, for example, saw air grow visible and dense as it cooled into mist and then rain, and assumed it would condense further into earth and rock [source: Encyclopaedia Britannica; Encyclopaedia Britannica; Cohen].

Later, Plato, always the overachiever, tapped four elements for his world: earth, air, fire and water. Aristotle added a fifth, ether, to describe heavenly bodies. By mixing and matching these elements, they could explain, for example, why wood was solid (part earth), but also floated (part air) and burned (part fire) [sources: Armstrong ; Plato ].

The underlying idea -- that, as Democritus said around 440 B.C.E., all matter consists of imperceptibly tiny things -- approached the truth, but useful evidence of real atomic theory lay far in the future, in Robert Boyle's 1662 experiments with air pressure and vacuums. It would take another century-and-a-half before English chemist John Dalton would advance an accepted atomic theory in 1803 [source: Berryman].

Whence does life arise? How, asked early sources, can maggots simply appear in a corpse or oysters just show up on the seafloor? Greek natural philosophers, who thought that all matter held inherent qualities, said life could arise from base matter, given the right conditions. Along similar lines, the ancient Chinese thought bamboo spawned aphids [sources: Brack; Simon].

This idea of spontaneous generation would lead to some delightful experiments, absurd findings and voluminous vitriol spilled by the likes of Voltaire and his 18th-century contemporaries. But the laying of scientific eggs really began in the early 17th century, when Flemish physician Jan Baptista van Helmont said mice would spontaneously arise from a soiled shirt placed in a vessel containing wheat grains, and that scorpions could spawn from a basil-lined brick mold [sources: Brack; Simon]. No word yet on whether a live hamster will issue from a Jamba Juice made with chia seeds and whey protein.

En route to the truth, the science world would detour through two hotly competing theories: Preformationists said all embryos existed, fully formed, in eggs or sperm (which some claimed were like infinite matryoshka dolls reaching back to Adam and Eve), while the epigenesists argued that life arose from other matter but couldn't agree on the underlying force [sources: Alioto ; Maienschein].

The resulting arguments were vicious and frequently ludicrous, but efforts at disproving spontaneous generation ultimately drove improvements in scientific rigor and experimental design that helped yield the right answers [source: Encyclopaedia Britannica].

As our previous example demonstrates, even after the advent of the scientific method, new theories can require some time to overcome the force of authority and tradition, especially if the old ways appear to work.

Take miasma theory. Dating back at least to Hippocrates, it attributed illnesses to foul airs, which it blamed on harmful plant or animal exhalations or tiny bits of windborne, decaying matter. Because the idea drove healthful reforms in housing and sanitation, it often succeeded in reduced cases of illness, so it's no wonder it became popular in smelly, overcrowded Victorian London. Nevertheless, by masking the true culprit (bacteria), it contributed to many unnecessary deaths [sources: Science Museum UK; Sterner; UCLA].

In a somewhat ironic twist, one of London's leading proponents of miasma theory helped to disprove it, at least where cholera was concerned. William Farr, a pioneer of epidemiology and health statistics, provided vital cluster data during London's 1854 cholera outbreak. John Snow famously used this data to trace the waterborne disease to a Broad Street water pump. His work, and that of pioneers like Ignaz Semmelweis and Joseph Lister, would later help Louis Pasteur and Robert Koch prove germ theory. But, for now, it demonstrated the scientific method's invaluable capacity for self-correction [sources: BBC; Science Museum UK; UCLA].

Clearly, medicine was slow to emerge as a respected and rigorous field of study. Case in point: Mary Toft, the woman who in September 1726 convinced at least a dozen doctors that she could give birth to dead rabbits and rabbit parts. Repeatedly.

Let's pause to let that sink in.

Although the scientific method was well-established in some circles, medicine remained a stew of ideas, peppered heavily with quackery and pet theories. The burgeoning field of heredity still accepted maternal impression, the millennia-old idea that whatever a pregnant woman saw or felt could physically alter her unborn child. In one remarkable tale, a newspaper reported that an alleged father's name "appear[ed] in legible letters in his infant son's right eye" [sources: Encyclopaedia Britannica; Davis; Pediatrics ; University of Glasgow].

Clearly, argued consulting experts, poor Mary Toft had suffered a startling, rabbit-related encounter that had transformed her into a bunny-birthing dynamo.

Toft carried off the hoax for months, enjoying national celebrity, fooling numerous physicians and attracting the attention of King George I. A few experts, like German surgeon Cyriacus Ahlers, offered discrediting scientific evidence, noting that some "newborn" dead rabbits had air in their lungs and stool containing straw, grass and grain. But it was not until someone caught her mother-in-law hare-handed buying small rabbits, and under threat of painful reproductive exploratory surgery, that Mary confessed [sources: Encyclopaedia Britannica; Davis; Pediatrics ; University of Glasgow].

If 18th-century physiology was such a mess, you can imagine how early medicine must have played out. On the one hand, access to dissection subjects drove great advances in anatomy and physiology as far back as 300 B.C.E. On the other hand, every correct conclusion seemed counterweighted by superstition and social prejudice.

Greek physician Praxagoras (fourth-century B.C.E.) differentiated veins from arteries, but thought arteries carried air (likely because corpse arteries are often empty). In the second century, Galen carried on this tradition, but added that blood was made in the liver, which he said imbued it with "natural spirit," and swirled around the body in veins. It did not pump so much as it sloshed. Once it mixed with "vital spirit" from the lungs, blood was consumed by organs, which "attracted" it the way lodestone attracts iron. Blood also reached the brain via hollow nerves, he said, where it absorbed "animal spirit" [sources: Aird; Galen; West].

These notions held on until William Harvey published his game-changing "On the Motion of the Heart and Blood in Animals" in 1628. Others, such as Arab scholar Ibn an-Nafis, who died in 1288, had earlier made several corrections, but the Western world remained unaware of his work. Another predecessor, Spanish physician Miguel Serveto described circulation correctly in the 16th century, but wrapped his findings in a religious screed which, like Serveto himself, ended up burned on a pyre [sources: Aird; Cambridge Modern History ; West].

When Galileo demolished geocentrism, he also tore down several other cherished (but wrong) Aristotelian views. Aristotle explained motion by asserting that all matter had a proper place to which it tried to return, and that heavier objects should fall faster than lighter ones. But through meticulous experimentation, Galileo showed that objects falling or rolling downhill accelerate at the same constant rate, which we call acceleration due to gravity [sources: Alioto ; Dristle].

Aristotle had also argued that a moving object in its natural place, such as a ball rolling along the ground, would gradually stop because it was its nature to stay there. But as Galileo realized, and as Newton later formalized, the apparent slowing of moving objects was caused by friction; take that away, and a ball would roll on forever [sources: Alioto ; Dristle; Cardall and Daunt; Galileo ].

Along similar lines, the Aristotelian-Ptolemaic view of physics implied that a piece of shot dropped from a ship's crow's nest would land some distance behind the mast because the ship moved forward while the ball fell. But Galileo showed that the cannonball, which shares the ship's forward velocity, would actually fall straight to the base of the mast. In these ways, Galileo, one of the fathers of experimental science, prefigured Newton's laws of motion , as well as the concept of reference frames while also disproving some of the chief arguments against Earth's movement [sources: Cardall and Daunt; Galileo ].

No survey of the crazy things we believed before the scientific method would be complete without some mention of the weird and horrifying practices we once considered medicinal.

Remember all that business about humors (blood, phlegm, black bile and choler, aka yellow bile)? Well, imagine what kind of medical treatments might arise from such a bodily fluid-focused approach, and you have a sense of what humoral medicine was like: diagnoses based solely on the smell of feces , urine, blood or vomit; physicians who prescribe forced vomiting, frequent bloodletting and iffy enemas to balance the body out. What it lacked in effectiveness it made up for in sheer life-threatening danger. Not surprisingly, people stuck to prayer and folk remedies whenever possible [sources: Batchelor ; Getz ].

As for bleeding hemorrhoids, some doctors viewed them as natural humor-balancers, useful for relieving mania, depression, pleurisy, leprosy and dropsy (edema). Of course, if bleeding got out of hand, it was time to break out the red-hot pokers. It's amazing what people will sit still for [sources: Encyclopaedia Britannica; Encyclopaedia Britannica; DeMaitre ].

Author's Note: 10 Things We Thought Were True Before the Scientific Method

All theories rest, to some degree, on assumptions. We try to minimize them, because they make up hidden cracks in science's foundations but, short of actual omniscience, they're pretty much unavoidable.

When a theory falls apart, it's often because an assumption was wrong. Science is always an educated best guess, after all -- it's just that, under modern scientific method, we subject those conjectures to rigorous tests through prediction, observation, repeatable experiments and peer review. Because of this, even when we're off the beam, we aren't far off and, in any case, it's only temporary. Einsteinian physics replaced Newtonian, but Newton's laws still work in every situation we typically encounter in our lives, so we still use them. If, someday, someone supersedes Einstein, it will only be in some limited sense (replacing an underlying assumption or mechanism, likely). Einstein's predictions simply work too well to be wholly wrong.

And in the end, that's the point. Science is what works.

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