A glance at history

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A glance at history

What makes science scientific?

A widely cited answer to this question is the development during the 17th century of an experimental tradition. Additionally, there was the banning by the Royal Society of debates that could not be settled by observation or experiment.

This edict owed much to Francis Bacon who had argued that scientists should only make inferences strictly from observation. The practical effect of the Royal Society edict was to remove philosophical and theoretical subjects from the scientific agenda.

However, science flourished before the great experimentalists such as Boyle arrived. Its prior advance was largely a conceptual one, whose famous experiments occurred in the minds of its practitioners as in the case of Galileo, or were fortuitous occurances, such as with Newton. Such historical precedents are at odds with a picture of a strictly experimental science. At present, as with Galileo and Einstein, new concepts often result from thought experiments or from mathematical juggling far removed from any laboratory. Furthermore, many of the great scientific revolutions, such as the Copernican revolution, have involved a triumph of reason over evidence.

Many however continue to view science as they imagine it was in the days of Newton and Galileo and require of scientists that they conform to these role models. However, Renaissance and modern science are quite different, and crucial to the transformation of science has been the rise in the importance of probability and the development of the human or interpretative sciences.

There were two forms of knowledge at the time of the Renaissance, scientia and opinio. Scentia aimed at certain knowledge, which led to a single rational conclusion given a common starting point. In this tradition mathematics was seen as the queen of the sciences. It is still single rational conclusions that many scientists think they are seeking.

Opinio, in contrast to scientia, took the appearance of things very seriously. Appearances were signs. Opinio was about interpreting those signs or determining their significance. As the term suggests, this approach led to something much less certain and much less respected than true knowledge.

The practitioners of opinio were typically medical practitioners, and the purpose of reading signs was to intervene in nature to cure illness, rather than to find out some essential truth.

The problem with signs lay in their interpretation. Some were more trustworthy than others. It is in the sense of trustworthyness that opinio became more scientific with the arrival of the idea of probability after 1660.

With the arrival of the notion of probability and a mathematics to quantify levels of probability, given a large enough sample of signs, it became possible to make a rational stab at probable if not certain truth. The interpretation of signs became less magical and more a repeatable intervention.

The probability of opinio became the dynamic of scientific advance. With the rise of probability there emerged the possibility of diagnostic rather than demonstrative experiments. In contrast to the demonstrative experiment, which ideally was a demonstration of a necessary truth, a diagnostic experiment proceeded from ignorance to knowledge.

This approach has an inbuilt dynamic of advance-diagnosis, prognosis, experiment-since if the diagnosis was called into question a further analysis was required. It can be argued that this is the dynamic responsible for the progress of modern science.

The rise of probability has been strongly resisted. The turn to probability has been seen as a resort to second grade knowledge, to mere opinion. Increasingly however statistics have become the master tool of science. And from this point of view physics has been one of the last sciences to become modern. The introduction of probability schedules into the heart of physics with the quantum revolution, and the realization that even physics only offers relative and probable truth, mark the final triumph of opinio over scientia.

Both the philosophy and mythology of science have until recently concerned themselves with scientia rather than opinio. Theory has been pre-eminent over practice and experiments have been seen as a method to test theories rather than as a source of knowledge.

At present it is still the case that research funds are more forthcoming for testing a specific hypothesis rather than simply doing something because it has never been done before.

Several features of a science dominated by probability and experiment deserve note:

  1. Probabilities and correlations derive from signs (observations) they are not mental fictions or conjectures. Correlations cannot be refuted by a single contrary instance, as for example can be Popper's conjectures. Scientia would want to argue; all swans are white, opinio would argue that it is probable that most swans are white.
  2. Probability leads to generalisation. Not the universal and necessary truths of scientia, but generalisations that hold across a specified range of concrete conditions under the proviso that other things are equal. As more and more detail is found out the practice of science becomes much more specialised.

It is worth noting, (I hope!), that if modern science is all about holding best possible opinions and attending ever more closely to concrete detail, and that it does so empirically by virtue of this attention being a collaborative exercise, then the social sciences can, in some respects, and for some particular purposes, fit this characterisation of the scientific enterprise.