The lab that I work in has these weekly ‘physics’ talks, where someone from the lab has to present a talk on something science-y that may interest everyone else. I call them physics talks, mainly because they are usually about MRI physics. But I gave a talk recently, and I presented on some of the current problems (that I read about) in modern science. The three problems I identified were:
- The over-zealous use and interpretation of the null-hypothesis statistical test;
- Unconscious manipulation of the experiment/data to get positive results;
- Publication biases, the focus on researchers to publish quantity and not quality, and over-abundance of published articles
At the beginning of that talk, though, I presented a short history of the scientific method. That’s what this post is going to summarize. I may or not write another post later on on those three problems…
Thales (b. 625 BCE): first to refuse to believe supernatural, religious or mythological explanations
Plato (b. 427 BCE): deductive reasoning (i.e. logic).
Platonic idealism: “we are discovering what is actually out there”
Aristotle (b. 384 BCE): earliest instance of a ‘scientific method’.
Introduced early form of ‘empiricism’: induction.
~250 BC: First library with an index (Library of Alexandria)
Ibn al-Haytham (Alhazen; b. 965 CE): observation, experiments, and rational argument: 1. Explicit statement of a problem, tied to observation and to proof by experiment 2. Testing of hypothesis using experimentation 3. Interpretation of data and formulation of conclusion using math 4. Publication of findings
Roger Bacon (b. 1214): repeating cycle of observation, hypothesis, experimentation, then independent verification (thus the need to write everything down in precise detail).
Galileo Galilei (b. 1564): Introduced thoughts experiments into science.
Imagine two objects, one light and one heavier than the other one, are connected to each other by a string. Drop this system of objects from the top of a tower. If we assume heavier objects do indeed fall faster than lighter ones (and conversely, lighter objects fall slower), the string will soon pull taut as the lighter object retards the fall of the heavier object. But the system considered as a whole is heavier than the heavy object alone, and therefore should fall faster. This contradiction leads one to conclude the assumption is false.
Demonstrated the true usefulness of mathematics in science.
Francis Bacon (b. 1561): procedure for isolating and further investigating the cause of a phenomenon.
Rene Descartes (b. 1596): axioms not through induction (Aristotle), but through reason alone. Beginning of rationalism.
John Locke (b. 1632): investigate for yourself, instead of trusting authority: knowledge must be based on experience.
Isaac Newton (b. 1643): focused on Bacon’s empiricism, thought rationalism was fallible to sense and the mind.
- We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances.
- Therefore to the same natural effects we must, as far as possible, assign the same causes.
- The qualities of bodies, which admit neither intension nor remission of degrees, and which are found to belong to all bodies within the reach of our experiments, are to be esteemed the universal qualities of all bodies whatsoever.
- In experimental philosophy we are to look upon propositions collected by general induction from phænomena as accurately or very nearly true, notwithstanding any contrary hypotheses that may be imagined, till such time as other phænomena occur, by which they may either be made more accurate, or liable to exceptions.
1665– Scholarly Journals established
1675– Peer review begun
David Hume (b. 1711): problem of induction; plus cannot appeal to inductive reasoning by appealing to its past success.
Immanuel Kant (b. 1724): marriage of rationalism and empiricism.
William Whewell (b. 1794): hypothetico-deductive method: scientific inquiry proceeds by formulating a hypothesis in a form that could conceivably be falsified by a test on observable data. A test that could and does run contrary to predictions of the hypothesis is taken as a falsification of the hypothesis. A test that could but does not run contrary to the hypothesis corroborates the theory. It is then proposed to compare the explanatory value of competing hypotheses by testing how stringently they are corroborated by their predictions.
Charles Sanders Peirce (b. 1839): Pioneer of statistics.
Promoted the frequency interpretation of probability (probability of an event is its relative frequency over time).
Integrated induction (empiricism) and deduction (rationalism) (and added abduction: guessing).
Held that science achieves statistical probabilities, not certainties, and that chance, a veering from law, is very real.
With repeated measures design, introduced blinded, controlled randomized experiments.
Introduced terms “confidence” and “likelihood”.
John Dewey (b. 1859): science is pragmatic and instrumental: an ideology or proposition can be said to be true if and only if it works satisfactorily, that the meaning of a proposition is to be found in the practical consequences of accepting it, and that impractical ideas are to be rejected.
Karl Popper (b. 1902): falsification: scientific theory should make predictions (preferably predictions not made by a competing theory) which can be tested and the theory rejected if these predictions are shown not to be correct.
Thomas Kuhn (b. 1922): rejected Popper’s view that there was a single method that applies to all science and could account for its progress. Scientists work within a series of paradigms, and there is little evidence of scientists actually following a falsificationist methodology.
Imre Lakatos (b. 1922): For Lakatos, what we think of as a ‘theory’ may actually be a succession of slightly different theories and experimental techniques developed over time, that share some common idea: their ‘hard core’. Lakatos called such changing collections ‘Research Programmes’. The scientists involved in a programme will attempt to shield the theoretical core from falsification attempts behind a protective belt of auxiliary hypotheses. Whereas Popper was generally regarded as disparaging such measures as ‘ad hoc’, Lakatos wanted to show that adjusting and developing a protective belt is not necessarily a bad thing for a research programme. Instead of asking whether a hypothesis is true or false, Lakatos wanted us to ask whether one research programme is better than another, so that there is a rational basis for preferring it.
Paul Feyerabend (b. 1924): Epistemological anarchism: there are no methodological rules which are always used by scientists. He objected to any single prescriptive scientific method on the grounds that any such method would limit the activities of scientists, and hence restrict scientific progress.
Bayesian inference (began to be accepted and used around the 1980s): acknowledges one’s ability to alter one’s beliefs in the face of evidence. This has been called belief revision, or defeasible reasoning: the models in play during the phases of scientific method can be reviewed, revisited and revised, in the light of further evidence.
That’s about all I could find (obviously simplified). Is there a trend? From what I can tell, we have moved from thinking that the discoveries made with science help to uncover the neumenon, or platonic ideal, and have instead opted for the pragmatic interpretation. This includes the acceptance of statistics and probability to describe the world; the shift from frequentist statistics to bayesian statistics; rejection of a deductive science (or “nomological-deductive“); rejection of a ‘true’ scientific method; etc.
At the same time, however, science has certainly been driving towards more and more objectivity: from having to publish your methods so that others may attempt to replicate your findings; controlled and blinded experiments; statistical significance; meta-analyses; etc.
One historical aspect that I did not add, since, if anything, it has obstructed scientific progress, is the addition of ethics: ethical treatment of people and animals. Now, that sentence may read as if I think that ethics was a bad thing to happen to science. And, sure, to science it’s a bad thing, but to sentient creatures, who should be the beneficiaries of science, it’s a wonderful thing (for what I hope are very apparent reasons; well, perhaps a utilitarian could argue against me…, but I won’t go into that).