‹Science does not rest upon solid bedrock. The bold structure of its theories rises, as it were, above a swamp. It is like a building erected on piles. The piles are driven down from above into the swamp […] and if we stop driving the piles deeper, it is not because we have reached firm ground. We simply stop when we are satisfied that the piles are firm enough to carry the structure, at least for the time being.›
Popper K., The Logic of Scientific Discovery, Routledge, 2005, p. 94
How do you learn to learn? Since the early XXth century, Philosophy of Science enjoyed a wide development, also as a result of the advent of Modern Physics.
In 1915, A. Einstein presented his theory on general relativity, suggesting that time was relative, depending on the frame of reference. At the same time, Newton’s law of universal gravitation proved to be a valid approximation only in weak field conditions and low speed.
Centuries-old structures were dismantled by theories difficult to prove, but logically firm.
The path of doubt is looming, that is the fulcrum of modern science.
From the truth to the false
The course of the twentieth century establishes the structuring of scientific thought as we know it today.
At the beginning of the century, the Vienna Circle, a group of philosophers and scientists oriented towards the reconsideration of the job of philosophy and science, played a key role.
What is science and what is not? The conception of the principle of verification (by M. Schlick) was a crucial hub, later objected by K. Popper (1902-1994), occasional attendee of the circle, to which he opposed the criterion of falsifiability.
The twentieth century, thus, saw the factual transition from: “A sentence is scientific if verifiable” (Vienna Circle), to “a sentence is scientific if falsifiable”, that is it can be subjected to a check that can disprove it.
The latter is the approach modern science is still using.
A framework where nothing can be said to be definitively true; a method that stops searching for evidence to confirm a theory, but in which, on the contrary, theories are subjected to a strenuous struggle for survival, such as in Darwin’s natural selection: the theory which resists most objections remains.
But why should we think like this?
Story of a turkey
A. Einstein famously said: “No amount of experimentation can ever prove me right; a single experiment can prove me wrong.”
The well-known German scientist had already pointed out the limits of the inductivist process.
This type of reasoning implies the creation of a universal rule, starting from the analysis of numerous particular cases. Bertrand Russell explains it well, telling us about a turkey, which decided to build up a worldview based on science as conceived by Vienna Circle neo-positivists.
«The turkey found that, on his first morning at the turkey farm, that he was fed at 9 a.m. Being a good inductivist turkey he did not jump to conclusions. He waited until he collected a large number of observations that he was fed at 9 a.m. and made these observations under a wide range of circumstances, on Wednesdays, on Thursdays, on cold days, on warm days. Each day he added another observation statement to his list. Finally he was satisfied that he had collected a number of observation statements to inductively infer that “I am always fed at 9 a.m.”. However on the morning of Christmas eve he was not fed but instead had his throat cut. »
(Bertrand Russell, 1912)
This metaphor effectively represents the limits of the previous inductivist method of reasoning which, from Vienna to the rest of Europe, strongly influenced the scientific method in the first decades of the twentieth century.
In fact, no matter how many specific cases can be enumerated as a proof for an assumption: nothing can guarantee that even the following agrees with the inference formulated. The cases to be considered for each individual experiment are infinite by type and quantity: it is impossible to experience them all.
In short: just because the sun has always risen, it is not sure it will do so tomorrow, as D. Hume effectively summarized in the XVIIIth century.
Twentieth century was decisive for the formulation of the scientific method as we conceive it today.
To K. Popper the merit of intuiting and codifying the real work of the scientist (from Galileo to Newton, Einstein, until the recent discovery of the Higgs Boson): to hypothesise strongly predictive theories, which are not always verifiable at the moment.
From then to now, the key of researches is doubt. Nothing can be said true definitively: these theories will remain valid until one of the repeated checks they are subjected to will disprove them.
Knowledge is no longer the accumulation of truth, but the rejection of errors. Theories must, however, be thrown.
After all, as Novalis said and Popper later quoted: “Theories are nets: only he who casts will catch”.
In a similar vein:
David Hume, An Enquiry Concerning Human Understanding
Thomas Kuhn, The Structure of Scientific Revolutions
Nassim Nicholas Taleb, The Black Swan
By Noemi Manghi