Science or pseudoscience?

Martin Gardner

The word pseudoscience is defined as follows in the Cambridge Dictionary:

a system of thought or a theory that is not formed in a scientific way

As for Wikipedia, it is defined like this:

statements, beliefs, or practices that claim to be both scientific and factual but are incompatible with the scientific method

We can deduce that pseudoscience is a theory or discipline presented as scientific, but not really scientific. The distinction between science and pseudoscience is important, because there are many pseudosciences, almost more than sciences, although sometimes it is difficult to distinguish them, because throughout history, ideas about what is scientific and what is not, have changed.

The first thing to clarify is that an erroneous scientific theory, later shown to be false, is not pseudoscience. While it was in effect, it was perfectly scientific. The fact that it has been possible to falsify it (to prove that it is mistaken) shows that it was indeed scientific. For instance:

• Ptolemy’s cosmological theory, which considered the Earth an immobile body at the center of the solar system, was not falsified until the 19th century, when Bessel detected the first stellar parallax in 1838, which showed that the Earth moves around of the sun, and in 1851 by the Foucault pendulum, which showed that the Earth revolves around its axis. Until that time, Ptolemy’s cosmology was scientific, although in practice it had been abandoned by almost all astronomers since the time of Newton.
• The phlogiston theory to explain chemical phenomena such as rust and combustion, which was in force for a century, until Lavoisier falsified it and replaced it with the oxidation theory.

Defending a theory after it has been convincingly falsified would be pseudoscience. I am not aware that there are now many advocates of Ptolemy’s cosmology or of the phlogiston theory, but there are defenders of flat-Earth cosmology, which is even older than Ptolemy’s, and in that case one can certainly speak of pseudoscience.

There are some cases of theories that, when they were proposed, were considered scientific, but later ceased to be so and were demoted to the level of pseudoscience. For example:

• Phrenology: Devised at the beginning of the 19th century and accepted as a science for more than a century, it asserted that it is possible to deduce the character and personality of human beings, as well as possible criminal tendencies, based on the shape and measurements of their skull, head and features.
• Eugenics: Devised during the 19th century by Francis Galton, Darwin’s cousin, its objective was to improve the human species through selective breeding, in the style of what is done with domestic animals. This social pseudoscience was discredited when the Nazis used it as a scientific basis to murder or sterilize millions of disabled, mentally ill, homosexuals, and those belonging to certain ethnic groups considered inferior, such as Jews and Gypsies. However, recently there have been attempts to recover it, (such as liberal eugenics, which tries to combine it with genetic engineering to improve the human species, with terrible practical results, such as the extermination of people affected by Down syndrome using selective abortion.

When fighting pseudosciences, scientists often find themselves at a disadvantage compared to our opponents, due to the peculiarities of the scientific method, which does not allow us to make clear statements and forces us to always leave the door open to the possibility of error in established theories. Let us look in this regard at a paradigmatic case.

Immanuel Velikovsky

In 1950, Immanuel Velikovsky published a book (Worlds in collision) that caused great controversy. His delusional scientific ideas were intended to offer naturalistic explanations for the miracles in the book of Exodus. Summarizing:

Around the year 1500 B.C. a giant comet was ejected from the mass of Jupiter and headed toward the inner solar system. After a series of orbits, during which it was about to collide several times with Mars and with the Earth, its orbit ended up in a circle and the comet became planet Venus. During his brushes with the Earth, he caused the ten plagues of Egypt, the parting of the Red Sea for the Israelites to pass through, the rain of manna in the desert, and the stopping of the rotation of the Earth during the battle of Joshua against the Amorites.

Velikovsky’s book provoked the outrage of astronomers but was slow to be refuted from a scientific point of view. The most notorious refutations were made by scientific popularizers such as Martin Gardner (who gave to this theory a chapter of his book Fads & Fallacies in the name of science, 1952-57) and Isaac Asimov, who gave it an article entitled Worlds in confusion, published in 1969 and compiled in his collection The stars in their courses, 1971. Finally, in 1974, the AAAS sponsored a scientific meeting to discuss Velikovsky’s theories, where astronomer and popularizer Carl Sagan read a 70-page article that later became a chapter in his book Broca’s Brain. In this article, Sagan went over the scientific problems in Velikovsky’s book one by one, but he always speaks like a scientist. He never says that those problems are final. For example, speaking of the circularization of the orbit of Venus, he says this:

The idea that Venus could have been converted, in a few thousand years, from an object in a highly eccentric orbit to its present orbit, which is… the most nearly perfect circular orbit of all the planets, is at odds with what we know about the three-body problem in celestial mechanics. However, it must be admitted that this is not a completely solved problem and that, although Velikovsky’s hypotheses most likely are wrong, there is still no full evidence against them.

Naturally, Velikovsky’s supporters hailed this way of posing the question as a triumph of their ideas.

It is curious that Sagan ended his analysis of Velikovsky’s theories as follows:

If we are forced to choose - and strictly we are not - is not the evidence for the God of Moses, Jesus or Muhammad better than the evidence for Velikovsky’s comet?

In his book The pseudo-science wars (2012) Michael Gordin concludes that telling apart science and pseudoscience is not easy. Perhaps the best way would be an adaptation of Judge Potter Stewart’s famous saying about obscenity: We know pseudoscience when we see it. And Martin Gardner says this:

The problem of determining the degree to which a theory is confirmed is extremely difficult and technical, and, as a matter of fact, there are no known methods for giving precise “probability values” to hypotheses… We shall be concerned, except for a few cases, only with theories so close to “almost certainly false” that there is no reasonable doubt about their worthlessness.

Meanwhile, the word pseudoscience is also used as a slur, to disqualify those who disagree with the dominant ideology. Thus, my posts in defense of the biologically orthodox assertion (human life begins with the fertilization of the ovum by the spermatozoon), have been taunted as pseudoscience, although they just explain what science has been saying about this question for over a century and a half. But when pro-abortion biologists confront me in subsequent debates, they never call pseudoscience what I say, knowing very well that my arguments are true; they always try to justify their ideas by arguing that the question of induced abortion is not scientific but corresponds to governments and parliaments. This is also what Nazis thought about the right to life of many human beings.

The same post in Spanish

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Manuel Alfonseca