West London Humanists and Secularists

The Chairman asked a physicist attending the meeting to open the discussion with a five minute summary on "scientific method".  Rather than the term "scientific method" he said he preferred to use the term "scientific thought" since no single  succinct method can encompass all that happens in the world of science. He stated that the purpose of scientific thought is to understand the natural world - the world we live in and the world of which we are a part. He also reminded us that scientific thought makes no attempt to concoct reasons why nature exists, it simply attempts to elucidate the way in which nature behaves.  

He outlined the main characteristics of scientific thought as follows:

1. The creative scientist takes, as input, particular descriptions, observations, experiments and measurements about the world - what might be deemed to be the facts - and uses them to develop models or theories which can be subjected to stringent tests.   
2. In seeking new ideas, scientific thinking more frequently argues from the "particular" to the "general" (induction) rather than from the general to the particular (deduction).  The result is an induced  hypothesis which has wide applicability and from which the supporting  "particulars" can be deduced.  The emergence and formulation of new and original scientific hypotheses involves highly creative processes that are often neither commonsensical nor otherwise obvious and which are aided by some of the same inspiration and intuition that is commonly associated with the less scientific creative endeavours of the human brain.   
3. Testing a new scientific hypothesis starts by showing that it reliably predicts the facts from which it draws and, in addition, predicts new facts not previously encountered.
4. The degree to which those new predictions are confirmed by new observations or by new experimental measurements is a determining factor in the eventual success of the hypothesis.  A further measure of success, particularly in the physical sciences, is the degree to which a hypothesis yields to mathematical reasoning and gives rise to sound mathematical expressions.
5. In time, the predictive success and mathematical consistency may validate the hypothesis sufficiently to raise its status to that of an accepted model or scientific theory. The theory embodies expressions of the regularity of nature normally referred to as Natural Law.
6. A good scientific theory rests on evidence derived from observations and measurements and survives until new evidence shows it to be inadequate.  Scientific and technical practice thrives on consensus by accepting a theory as a reliable working model of the way nature itself really behaves.  On the other hand, scientific progress is only possible by testing a theory to and beyond its limits to actively seek its falsity.   Thus scientific thought struggles to understand and refine the laws of nature as new evidence emerges.

The expectation of science is that any theory will eventually be proved false, or at least to be less general than was thought.  Newton argued from a particular idea of a falling apple to the motion of "heavenly bodies" in general when he formulated the Law of Universal Gravitation.  For most practical purposes his theory proved and still proves to be correct. But the first intimation that the law might be incomplete came in the mid 19th century when the observed advance in the perihelion of Mercury was greater than that predicted from Newton's Laws. It was Einstein's work on General Relativity that eventually led to a more refined theory which accounted for this observed discrepancy as well as for all the numerous other facts that did not need a revised theory.

General discussion raised a number of issues:

1. It was observed that the problem with theists is that, when they say they believe X, they are not saying they consider it to have a high probability of being true, which might be acceptable, but are saying that it is definitely true.  Worse, they are saying that it will remain true despite any evidence gathered that casts doubt on it.  
2. Used by humanists, the word "believe" is therefore quite risky.  Although it may be intended to signify "the evidence suggests" or "it is probable that", it will often be misinterpreted by theists who assume we are using it in the same way as they do.  This is why they often consider science as an alternative (and false) religion and assume that we view the Laws of Physics in the same way as they view their dogmas.  For them dogmas are true irrespective of any evidence, for scientists there is an assumption that even their most successful theories may eventually be proved false, or partially false, by new evidence. 
3. It was observed that saying "I think X" was always more appropriate than saying "I believe X" for humanists.  It was suggested that, as a group, we should try always to say "I think" rather than "I believe" in whatever context.
4. Science should be viewed as the great liberator from dogma, especially from dogma designed by the few to enslave the many.
5. Discussion also ranged over the issue of how far scientific thought could be applied - are there any areas of human experience (religion for example) where scientific thought must be considered quite irrelevant?  Our physicist's challenging claim that scientific thought is relevant to all human experiences was, on reflection, hard to resist.  This deserves further discussion.
6. "Where's the evidence?" should be a Humanist battle cry.