Falsifiability: Encyclopedia II - Falsifiability - Some examples

Falsifiability - Some examples

Claims about verifiability and falsifiability have been used to criticize various controversial views. Examining these examples shows the usefulness of falsifiability by showing us where to look when attempting to criticise a theory.

Non-falsifiable theories can usually be reduced to a simple uncircumscribed existential statement, such as there exists a green swan. It is entirely possible to verify that the theory is true, simply by producing the green swan. But since this statement does not specify when or where the green swan exists, it is simply not possible to show that the swan does not exist, and so it is impossible to falsify the statement.

That such theories are unfalsifiable says nothing about either their validity or truth. But it does assist us in determining to what extent such statements might be evaluated. If evidence cannot be presented to support a case, and yet the case cannot be shown to be indeed false, not much credence can be given to such a statement.

Falsifiability - Mathematics

Mathematical and logical statements are typically regarded as unfalsifiable, since they are tautologies, not existential or universal statements. For example, "all bachelors are male" and "all green things are green" are necessarily true (or given) without any knowledge of the world; given the meaning of the terms used, they are tautologies.

Proving mathematical theorems involves reducing them to tautologies, which can be mechanically proven as true given the axioms of the system or reducing the negative to a contradiction. Mathematical theorems are unfalsifiable, since this process, coupled with the notion of consistency, eliminates the possibility of counterexamples—a process that the philosophy of mathematics studies in depth as a separate matter.

How a mathematical formula might apply to the physical world, however (as a model), is a physical question, and thus testable, within certain limits. For example, the theory that "all objects follow a parabolic path when thrown into the air" is falsifiable (and, in fact, false; think of a feather—a better statement would be: "all objects follow a parabolic path when thrown in a vacuum and acted upon by gravity", which is itself falsified when considering paths that are a measureable proportion of the planet's radius).

Falsifiability - Ethics

Many philosophers have held that claims about morality (such as "murder is evil" and "John was wrong to steal that money") are not part of scientific inquiry; their function in language is not even to state facts, but simply to express certain moral sentiments. Hence they are not falsifiable.

Falsifiability - Theism

On the view of some, theism is not falsifiable, since the existence of God is typically asserted without sufficient conditions to allow a falsifying observation. God being a transcendental being, beyond the realm of the observable, claims about its existence can neither be supported nor undermined by observation. It is quite consistent for a theist to agree that the existence of God is unfalsifiable, and that the proposition is not scientific, but to still claim that God exists. This is, of course, a matter of interest for anyone who places stock in natural theology--the argument from design and other a posteriori arguments for the existence of God. (See non-cognitivism.) However, arguments relating to alleged actions, rather than the existence, of God may be falsifiable. See nontheism for further information.

Falsifiability - Conspiracy theories

There are other examples of theories, however, that are much less controversial as examples of unfalsifiable claims. Some so-called "conspiracy theories," at least as defended by some people, are essentially unfalsifiable because of their logical structure. Conspiracy theories usually take the form of uncircumscribed existential statements, alleging the existence of some action or object without specifying the place or time at which it can be observed. Failure to observe the phenomenon can then always be the result of looking in the wrong place or looking at the wrong time. Conspiracy theorists can, and often do, defend their position by claiming that lying and other forms of fabrication are, in fact, a common tool of governments and other powerful players and that evidence suggesting that a conspiracy did not occur has been fabricated.

Falsifiability - Economics

Many viewpoints in economics are often accused of not being falsifiable, mainly by sociologists and other social scientists in general.

The most common argument is made against rational expectations theories, which work under the assumption that people act to maximize their utility. However, under this viewpoint, it is impossible to disprove the fundamental theory that people are utility-maximizers. The political scientist Graham T. Allison, in his book Essence of Decision, attempted to both quash this theory and substitute other possible models of behavior.

Falsifiability - Historicism

Theories of history or politics which allegedly predict the future course of history have a logical form that renders them neither falsifiable nor verifiable. They claim that for every historically significant event, there exists an historical or economic law that determines the way in which events proceeded. Failure to identify the law does not mean that it does not exist, yet an event that satisfies the law does not prove the general case. Evaluation of such claims is at best difficult. On this basis, Popper himself argued that neither Marxism nor psychoanalysis were science, although both made such claims. Again, this does not mean, that any of these types of theories are necessarily invalid. Popper considered falsifiability a test of whether theories are scientific, not of whether theories are valid.

Falsifiability - Solipsism

In philosophy, solipsism is, in essence, non-falsifiable. Solipsism claims that the Universe exists entirely in one's own mind. This can straightforwardly be seen not to be falsifiable, because whatever evidence one might adduce that is contrary to solipsism can be, after all, dismissed as something that is "in one's mind." In other words, there is no evidence that one could possibly adduce that would be inconsistent with the proposition that everything that exists, exists in one's own mind. This view is somewhat similar to Cartesian scepticism, and indeed, Cartesian skepticism has been rejected as unfalsifiable as well by many philosophers.

Falsifiability - Physical laws

The laws of physics are an interesting case. Occasionally it is suggested that the most fundamental laws of physics, such as "force equals mass times acceleration" (F=ma), are not falsifiable because they are definitions of basic physical concepts (in the example, of "force"). More usually, they are treated as falsifiable laws, but it is a matter of considerable controversy in the philosophy of science what to regard as evidence for or against the most fundamental laws of physics. Isaac Newton's laws of motion in their original form were falsified by experiments in the twentieth century (eg, the anomaly of the motion of Mercury, the behavior of light passing sufficiently close to a star, the behavior of particle being accelerated in a cyclotron, etc), and replaced by a theory which predicted those phenomena, General Relativity, though Newton's account of motion is still a good enough approximation for most human needs. In the case of less fundamental laws, their falsifiability is much easier to understand. If, for example, a biologist hypothesizes that, as a matter of scientific law (though practising scientists will rarely actually state it as such), only one certain gland produces a certain hormone, when someone discovers an individual without the gland but with the hormone occurring naturally in their body, the hypothesis is falsified.

The range of available testing apparatus is also sometimes an issue - when Galileo showed Roman Catholic Church scholars the moons of Jupiter, there was only one telescope on hand, and telescopes were a new technology, so there was some debate about whether the moons were real or possibly an artifact of the telescope or of the type of telescope. Fortunately, this type of problem can usually be resolved in a short time, as it was in Galileo's case, by the spread of technical improvements. Diversity of observing apparatus is quite important to concepts of falsifiability, because presumably any observer with any appropriate apparatus should be able to make the same observation and so prove a thesis false.

Adapted from the Wikipedia article "Some examples", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki