In our current age of immense scientific discovery, we may feel a little pity when we look back at our ancestors. Condemned to look in vain to the sky for omens and portents, making meaningless sacrifices to a myriad of gods, lost in the mystery of the universe.
We however can relax, comfortably secure in our scientific knowledge, knowledge that has been painstakingly developed from careful application of the scientific method. The ultimate test of logic and rationality.
Well, maybe we shouldn't be feeling quite so comfortable, maybe science isn't so rational after all!
The scientist
Imagine a scientist, busily carrying out experiments at the frontier of scientific knowledge. Let's say she is the perfect scientist, the experiments are meticulously controlled and her observations are carefully recorded. Over a period of time, general trends emerge and these are sufficient for her to formulate a general hypothesis.
The hypothesis is then systematically tested by carefully controlled experiments and given time and a sufficient body of supporting evidence, the hypothesis is accepted. This is application of the scientific method, the same method used by Newton and all the scientific geniuses since.
Induction
The scientific method is one of induction - general theories are made based on repeated observations of nature. Observations of nature are given the highest status, if they disagree with the theory, inductive reasoning says we must change the theory. This all sounds perfectly good and reasonable except it leaves a very worrying problem.
Hume's problem
The 18th Century philosopher David Hume pointed out that this approach is neither logical nor rational, here's why. There is no logical rationale for stating that just because one event followed another in the past, it will also follow that event in the future. Magee uses the example of the sun rising. We 'know' that every morning the sun will rise but actually, how do we know this? We know it because we have seen it rise every day of our lives and hence we believe that tomorrow morning will be no different.
Rational?
The key word here is 'believe'. Logically speaking, just because something has occurred in the past, even repeatedly, does not mean it will occur in the future. We cannot make a rational argument that the sun will rise tomorrow because we cannot know for sure that the future will be the same as the past.
Our belief is based on our psychology and not on logic. Our psychological makeup leads us to believe in the regularity of nature, the scientific method of induction is based on the regularity of nature and hence the very foundation of science is built on human psychology rather than logic.
Where now?
This leaves us in a very tricky situation. We live in a world where science is held to be all powerful, the pinnacle of human achievement, we hold it in almost divine esteem. Yet we cannot justify it using the logical and rational principles we hold so dear.
However, while we may be more lost in the mystery of the universe than we thought, all is not yet hopeless...
The series 'Right and Popper' is based on the summary of Popper's philosophy written by Bryan Magee. The introductory post in the series can be read here.
Image by Brianarn
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