Can an hypothesis that is part of the scientific method have multiple parts which can be falsified or supported individually?

Let's say the experiments provide evidence that Part A models correctly describe reality while the experiments are falsifying Part B.

Are such hypotheses possible? Or must an hypothesis only have 1 part that can be supported or be falsified as a whole?

3 Answers 3


IMO, the issue is not very relevant.

In principle, nothing prevent to formulate "complex" hypothesis addressing multiple facts.

See William Whewell about confirmation :

“our hypotheses ought to foretell phenomena which have not yet been observed” (Novum Organon Renovatum, 1858); second, that they should “explain and determine cases of a kind different from those which were contemplated in the formation” of those hypotheses (1858); and third that hypotheses must “become more coherent” over time (1858).

Hypotheses ought to foretell phenomena, “at least all phenomena of the same kind,” Whewell explained. Whewell’s point here is simply that since our hypotheses are in universal form, a true hypothesis will cover all particular instances of the rule, including past, present, and future cases. But he also makes the stronger claim that successful predictions of unknown facts provide greater confirmatory value than explanations of already-known facts. Thus he held the historical claim that “new evidence” is more valuable than “old evidence.”

The modern approach to the logic of confirmation is known as the Hypothetico-Deductive method :

In its simplest form, the idea is that a theory, or more specifically a sentence of that theory which expresses some hypothesis, is confirmed by its true consequences. Carl Hempel’s description of the method illustrated by the case of Semmelweiss’ inferential procedures in establishing the cause of childbed fever has been presented as a key account of Hypothetico-Deductive method.

Hempel described Semmelsweiss’ procedure as examining various hypotheses that would answer the question about the cause of childbed fever. Some hypotheses conflicted with observable facts and could be rejected as false immediately. Others needed to be tested experimentally by deducing which observable events should follow if the hypothesis were true (what Hempel called the test implications of the hypothesis), then conducting an experiment and observing whether or not the test implications occurred. If the experiment showed the test implication to be false, the hypothesis could be rejected. On the other hand, if the experiment showed the test implications to be true, this did not prove the hypothesis true.

In conclusion, in order to be useful, the method must be applied to as much "simpler" hypothesis as we can, in order to be able to test it against facts.


The answer is 'yes' but the truth is almost a vacuous one. The single-part option is virtually impossible, so there is no comparison between the two cases to be made.

It would be unreasonable to assume that any hypothesis had only a single fact involved. The hypothesis has to be phrased in terms that are parts of other models that might still be independently falsified or that might be modified in ways that subtly alter the meaning of the terms involved. So this is the usual case, the hypothesis emphasizes a single extension to the existing body, but relies upon a complex of supporting structures that are all still open to falsification.

Also, what the author sees as so closely related as to be a single fact, is usually really multiple facts, when things play out in reality. The law of gravity is a single formula, but it has a few unspoken parts that could have failed, and that were criticized independently: the notion of action through a distance without a medium, the uniformity of space and spatial relations that make this law apply both in earthly and larger contexts, etc. Clearly this is somehow a single idea, but it is also a complex of interdependent ideas some of which could have been supported while others were rejected.


Here is the question:

Can an hypothesis that is part of the scientific method have multiple parts which can be falsified or supported individually?

An hypothesis may be rewritten as a conjunction of multiple statements each of which may be falsified individually by evidence. For example, consider the hypothesis that all swans are white used by Wikipedia to illustrate falsifiability.

For example, the claim "all swans are white" is falsifiable since it is contradicted by this basic statement: "In 1697, during the Dutch explorer Willem de Vlamingh expedition, there were black swans on the shore of the Swan River in Australia", which in this case is a true observation.

Note that the hypothesis, "all swans are white", can be rewritten as "all swans are birds of a certain kind and they are white". The part about the swans being birds of a certain kind was not falsified. The part about them being white was falsified and so it had to be modified.


"Falsifiability", Wikipedia https://en.wikipedia.org/wiki/Falsifiability

  • Just because you can rewrite it to have multiple parts does not mean that is allowed. I think what your answer requires are references to trustworthy sources. Dec 4, 2018 at 21:15
  • @RăzvanFlaviusPanda Think about what happens when something like "all swans are white" is falsified by finding a black swan. People don't through out the whole theory about swans. They don't throw out everything they know about swans. They throw out only the part that has been falsified and keep the rest. Dec 4, 2018 at 21:47

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