Stage 1Stage one is the 'what' phase: simply stated, it is about naming and categorising natural phenomena, a delineation of cause and effect. In a sense, it is about finding rational explanations for things and events at the expense of superstition and mysticism. In addition, it utilises the principle of parsimony, otherwise known as Occam's (or Ockham's) Razor: that the simplest explanation is usually correct.
Although there were a few clear moments of stage one in Ancient Greece - Eratosthenes' attempt to measure the size of the Earth using Euclidean Geometry being a prime example - it seems to have taken off in earnest with Galileo. Although his work is frequently mythologised (I follow the rolling weights rather than dropping objects from the Leaning Tower of Pisa brigade), Galileo most likely devised both actual and thought experiments to test fundamental findings, such as the separate effects of air resistance and gravity.
Of course, Galileo was primarily interested in physics but the other areas of science followed soon after. Systematic biology came to the fore in such practical work as the anatomical investigations of William Harvey - pioneer in the understanding of blood circulation - and the glass bead microscopes of Antony van Leeuwenhoek. The work of the latter, interestingly enough, was largely to understand how small-scale structure in edible substances created flavours. It's also worth thinking about how this research expanded horizons: after all, no-one had ever seen the miniature marvels such as bacteria. I wonder how difficult the engravers of illustrated volumes found it, working from sketches and verbal descriptions on sights they have never seen themselves? But then again, no-one has ever directly imaged a quark either…
Talking of biology, we shouldn't ignore Carl Linnaeus, the Swedish scientist who started the cataloguing methodology in use today. New Zealand physicist Ernest Rutherford may have disparagingly referred to all branches of science other than physics as mere stamp collecting but apart from the wild inaccuracy of his statement it is seemingly obvious that without various standards of basic definitions there is no bedrock for more sophisticated research.
The repetitive, largely practical aspect of the phase in such disciplines as geology and taxonomy meant that largely untrained amateurs could make major contributions, such as the multitude of Victorian parsons (of whom Charles Darwin was almost a member) who worked on the quantity over quality principle in collecting and cataloguing immense amounts of data. Of course, Darwin went far beyond phase one but his work built on the evaluation of evolutionary ideas (try saying that three times fast) that numerous predecessors had discussed, from the Ancient Greeks to John Ray in the late Seventeenth Century.
This isn't to say that stage one science will be finished any time soon. The Human Genome Project is a good example of a principally descriptive project that generated many surprises, not least that it is proving more difficult than predicted to utilise the results in practical applications. Although in the BBC television series The Kingdom of Plants David Attenborough mentioned that the Royal Botanic Gardens at Kew contains 90% of known plant species, there are still plenty of remote regions - not to mention the oceans - yet to yield all their secrets to systematic scientific exploration. In addition to the biota yet to be described in scientific records, the existing catalogues are in the process of major reorganisation. For example, the multitude of duplicate plant names is currently being addressed by taxonomic experts, having so far led to the finding of 600,000 superfluous designations. It isn't just plants either: a recent example was the announcement that DNA evidence suggests there is probably only a single species of giant squid rather than seven. It may sound tedious and repetitive, but without comprehensive labelling and description of natural elements, it would be impossible to progress to the next stage.
Stage 2Who was the first person to move beyond cataloguing nature to in-depth analysis? We'll probably never know, but bearing in mind that some of the Ionian philosophers and Alexandrian Greeks performed practical experiments, it may well have been one of them.
By looking to explore why phenomena occur and events unfold the way they do, our species took a step beyond description to evaluation. If art is holding a mirror up to nature, then could the second phase be explained as holding a magnifying glass up to nature, reducing a phenomenon to an approximation, and explaining how that approximation works?
For example, Newton took Galileo and Kepler's astronomical work and ran with it, producing his Law of Universal Gravitation. The ‘how' in this case is the gravitational constant that explained how bodies orbit their common centre of gravity. However, Newton was unable to delineate what caused the force to act across infinite, empty space, a theory that had to wait for stage three.
So different from the smug, self-satisfied attitude of scientists at the beginning of the Twentieth Century, the techniques of modern science suggest that there is a feedback cycle in which knowing which questions to ask is at least as important as gaining answers, the adage in this case being ‘good experiments generate new questions'. Having said that, some of the largest and most expensive contemporary experiments such as the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Large Hadron Collider (LHC) have each been principally designed to confirm a single hypothesis.
As recent evidence has shown, even some of the fundamentals of the nature, including dark matter and dark energy, are only just being recognised. Therefore science is a long way from recognising all first principles, let alone understanding them. Closer to home, that most complex of known objects, the human brain, still holds a lot of secrets, and probably will continue to do so for some time to come.
Though microelectronics in general and computers in particular have allowed the execution of experiments in such fields as quantum teleportation, considered close to impossible by the finest minds only half a century ago, there are several reasons why computer processing power is getting closer to a theoretical maximum using current manufacturing techniques and materials. Therefore the near future may see a slowing down in the sorts of leading edge experimental science that has been achieved in recent decades. But how much progress has been made in phase three science?
Stage 3This is more difficult to define than the other two phases and can easily veer into philosophy, a discipline that has a poor press from many professional scientists. Physicist Richard Feynman for example is supposed to have disparaged it as ‘about as useful to scientists as ornithology is to birds'. Despite this - and the probability that there as many philosophies of science as there are philosophers - it's easy to see that the cutting edge of science, particularly theoretical physics, generates as much discussion over its validity as any work of art. If you've read one of the myriad critiques of superstring theory for example, then you will know that it can be viewed as a series of intellectual patterns (accompanied by diabolical equations) that may never be experimentally confirmed. In that case is string theory really just a collection of philosophical hypotheses, unproven by experiment or observation and likely to remain so? The minuteness of the scale (an underwhelming description if ever there was one) makes the prospect of directly recording strings themselves - as opposed to their effects - highly unlikely.
If that is the case then just where can you draw the line between science and philosophy? Of course one of the fundamental tenets of a valid hypothesis is to make testable predictions that no other hypothesis can account for. But with over a century of theories that increasingly fail to follow common sense or match everyday experience perhaps this is a sign of approaching maturity in science, as we finally advance beyond the crude limitations of our biological inheritance and its limited senses. Surely one key result of this is that the boundaries between new ideas promulgated by scientists and the thoughts of armchair philosophers will become increasingly blurred? Or is that just fighting talk?
Whereas scientists engaged in phase two investigations seek to find more accurate approximations for phenomena, phase three includes the search for why one theory is thought to be correct over another. A prominent example may help elucidate. Further to Galileo in phase one and Newton in phase two, Einstein's General Relativity, which explains the cause of gravity via the curvature of spacetime, is clearly an example of phase three. Of course, contemporary physicists would argue that Einstein's equations are already known to be lacking finality due to its incompatible with quantum mechanics. Herein lies the rub!
One problem that has caused dissension amongst many scientists is a possibly even more ‘ultimate' question: why is the universe finely tuned enough for life and more than that, intelligent life, to exist? The potential answers cover the entire gamut of human thought, from the conscious design principle supported by some religiously-minded scientists, to the invocation of the laws of probability in a multiverse hypothesis, requiring an immense number of universes all with the different fundamentals (and therefore including a lucky few capable of producing life). But the obvious issue here is that wouldn't Occam's Razor suggest the former is more likely than the latter? As Astronomer Royal Sir Martin Rees states, this is veering into metaphysical territory, which except for the scientists with religious convictions, is usually an area avoided like the plague. However, it may eventually become possible to run computer models that simulate the creation of multiple universes and so as bizarre as it seems, go some way to creating a workable theory out of something that to most people is still a purely philosophical notion. Talk about counting angels on a pinhead!
I can't say I'm entirely convinced by my own theory of three stages to science, but it's been interesting to see how the history and practice of the discipline can be fitted into it. After all, as stated earlier no-one has ever observed a quark, which in the first days of their formulation were sometimes seen as purely mathematical objects any way. So if you're doubtful I don't blame you, but never say never...