Introduction
For one to understand Karl Popper’s assertion that a scientific theory is not logically verifiable, it is essential to comprehend the underlying scientific philosophy from his perspective. Popper is considered unique in his outlook among other contemporary philosophers as he accepts the Humean Critique of Induction and seeks to build upon its validity. This particular critique challenges the grounds that we develop our beliefs about unobserved phenomena based on inductive inferences. In plainer terms, Hume questions the logic behind humans making assumptions on the validity of that which we cannot observe, based on the current state of the world.
Main body
Popper extends the Humean critique by arguing that induction is never wholly and accurately used within science. In extension, he refutes the Newtonian insistence on the formation of scientific theories using ‘pure’ observation. Instead, Popper insists that using pure observation to develop theories is misguided on the fact that all theories are selective. As such, there can be no true theory-free observation. This observation in itself destabilizes the conventional view of many scientific philosophers who held that science is distinguishable from non-science on basis of its inductive methodology. Popper’s assertions, however, lead to revisiting a persistent question: What is the distinguishing characteristic of science from non-science?
According to Popper’s arguments, there is no unique methodology that distinguishes science from non-science. Science, much like any other human activity, is organic and is concerned primarily with problem-solving. However, if a distinguishing methodology were to be implemented, it would not be that of inference, but rather of falsifiability. This substitute theory of falsifiability is a critical element of Popper’s eventual assertion that a scientific theory cannot be logically verified.
Falsifiability is defended by Popper in that it is easy to obtain supporting evidence for virtually any theory. In fact, this accreditation of a theory should be considered if it was positively arrived at from a relatively risky prior prediction that may have turned out false. This entire practice, therefore, constitutes a scientific theory, which as per Popper’s argument, is only scientific if it can be discredited by a conceivable event. An extension of this assertion, it follows that a genuine test of a scientific theory according to Popper would constitute attempting to discredit or falsify it; whereby arriving at one genuine instance which counters the initial provision of the theory falsifies the entire theory. Popper presented this theory of falsifiability as a vital step towards the solution of two philosophies, namely the problem of induction and the problem of demarcation.
It would be correct, however, to assert that Popper’s theory of falsifiability is synonymous with testability as the latter applies to testing that a hypothesis is incorrect, which is the cornerstone on which Popper based his theory of falsifiability. Based on Popper’s assertion of falsifiability being a defining characteristic of a scientific theory, no amount of experimentation can prove the validity of a scientific theory. However, a single experiment can prove that a theory is incorrect. For instance, a contemporary example of a scientific theory would be the hypothesis that “Aliens do not exist.” Based on Popper’s argument, this constitutes a genuine scientific theory in that it can be falsified by the singular instance of observing an alien.
The idea of a scientific theory, in Popper’s perspective, is therefore rather prohibitive. This is primarily by implication, whereby the definition of a scientific theory forbids specific events, observations, or occurrences. This nature of a scientific theory based on falsifiability, however, dictates that a theory can be tested and falsified, but it can never be logically verified. In fact, Popper does insist that the fact that a theory has withstood a lot of vigorous testing does not lend to the inference that it is verified. Rather, we should appreciate that the theory has received a great deal of accreditation and can, therefore, be held provisionally as the best available theory until it is either falsified or surpassed by a better theory with higher degrees of accreditation.
A distinction with the philosophy of falsifiability should, however, be drawn between logical verification, and methodological verification. The logic is fairly uncomplicated. For instance, if we observed a single red-colored frog, then it cannot be the case that all frogs are green. Therefore, from a logical perspective, all scientific theories are irrefutably falsifiable despite not being irrefutably verifiable. From a methodological perspective, the philosophy becomes much more complicated due to a seemingly simple assertion; that no experiment is free from human error. This recognition of the fact that no observation is completely free from the possibility of human error, therefore, leads to the much harder question of whether an experimental result is what it ought to be, or even appears to be.
Popper does draw the distinction of logical verification and methodological verification in his philosophy of falsifiability. He allows for the fact that, while a single conflicting instance of a previously held scientific theory is sufficient to logically falsify it, a single counter-instance may not be enough to methodologically falsify a scientific theory. This distinction can be observed in the contemporary application of science, whereby scientific theories are retained and held, despite the fact that there exists available evidence that conflicts with them. This conundrum does, however, lend back to Popper’s earlier assertion that there is no unique methodology to science. As such, there exists to single method to a scientific theory, whether that be an inductive reference, experience, and so forth.
This assertion is also one that Einstein agreed with; that there is no single logical path that leads to the highly universal laws of science. However, while Einstein argued that logical paths that dictate the theory of science are arrived at through intuition based on an intellectual curiosity of the objects under study (Billauer, 2016), Popper holds that science starts with problems and not observations. In Popper’s perspective, the presentation of a problem to a scientist is what prompts the individual to make observations. These observations are not ‘pure’, as Newtonian thought dictates, but are otherwise theory-laden and particularly designed to test a given theory that might provide a satisfactory solution to the problem.
Conclusion
Despite Popper’s assertions, the philosophy of falsifiability has been implemented extensively in scientific thought. It lends, inexorably, that a scientific theory can not be logically verified but can be instead falsified, which allows scientists to continually test existing theories of what is currently known. Also, it graciously allows for the possibility of other more accurate and better-corroborated explanations to be formulated and equally considered which in itself is very scientifically attractive and helps the overall progression of science. Finally, Popper’s assertion that there is no unique methodology to science is also attractive in that scientists that do not subscribe to the philosophy of falsifiability are not necessarily uncredited as unscientific, but also allows for their theories to be rigorously tested for falsifiability.
Reference
Billauer, B.P. (2016) ‘Admissibility of Scientific Evidence under Daubert: The Fatal Flaws of Falsifiability and Falsification’, BUJ Science & Technology. 22(1), pp. 21-33.