19: Philosophy of Science:
The Scientific MethodSummary by: Jeff McLaren Induction and Deduction
Induction is a form of reasoning in which you move from particular examples to a universal claim. But you can never be sure that you have enough particular examples to justify the universal claim.
Deduction is a form of reasoning in which you move from universal laws to particular claims. But you can never be sure that you have accurate universal laws.
The scientific method starts with an observation. Then the scientist tries to explain/describe the observation by using induction to formulate a guess or a hypotheses. Assuming the hypotheses to be a universal law, the scientists checks it using deduction to test if the hypotheses is true under different circumstances. The test is an experiment whose results become a new observation or the results become evidence of the hypotheses' accuracy.
Francis Bacon and René Descartes are the two philosophers who are recognized as ushering in modern science. Both philosophers realized that induction and deduction are needed in thinking but each one emphasized one at the expense of the other. Bacon championed an experiment-intensive, inductive approach to knowledge of nature that minimized both mathematics and an active role for mind. Descartes championed a mathematics-intensive, deductive approach that assigned a central role to mind and only a marginal role to experiment.
Both disagreed on many core issues but they did agree on four basic assumptions that all scientists continue to assume today. 1) The task of science is to frame descriptions and/or explanations of nature in terms of natural causes – not spiritual causes. 2) Nature is a closed system; that means that nothing fundamental to nature is destroyed or created – this assumption has morphed repeatedly in the history of science; today we say: energy cannot be created or destroyed. 3) Knowledge of nature must be based on experience – not on authority. 4) Mathematics is a useful language for describing/explaining natural phenomena.
Bacon argued that the key to knowledge of nature was not genius, inspiration or mystical revelation but a 'mechanical' method that reveals laws of nature in empirical data. Bacon claimed that the human mind was an obstacle to knowledge of nature. Bacon claimed that we are all inherently drawn to four Idols of the Mind that lead us into error:
1) Idol of the Tribe: the tendency to perceive more order and regularity than truly exists.
2) Idol of the Cave: weaknesses in reasoning due to particular values, likes and dislikes.
3) Idol of the Marketplace: science's use of metaphors and/or special meanings of normal vocabulary.
4) Idol of the Theater: the following of academic dogma uncritically.
To overcome these Idols of the Mind, Bacon proposed a mechanical method in which the procedure would guarantee that no errors would enter into the process. If one eliminates errors then one ought to be left with the truth. His method of controlled induction was the solution to the problem of acquiring knowledge of nature.
1. Collecting Data: collecting all relevant data, without any presuppositions.
2. Analyzing the Data: look for suggestive correlations in the data.
3. Then comes the extended process of experimentation to test possible correlations: the formation of hypotheses; further testing; and upon confirmation comes knowledge of nature’s laws.
For Descartes, the mind is the solution, not the problem. True knowledge about the world 'out there,' is in the mind, and only deductive reasoning can generate that knowledge. Mathematics is the key to scientific knowledge, while experiment is a tool of limited value, to be used cautiously because its results are easily open to two or more interpretations. Descartes believed that deductive reasoning was the only way to achieve universal, necessary, and certain knowledge of nature.
Both Bacon and Descartes had to overcome skepticism of method – that is that in their times science did not have the respect it enjoys today. Today's problem is that everything claims to be 'scientific' but many claimant do not deserve the status of 'science'. This is the problem of demarcation. How can we say that chemistry and physics are sciences but not astrology? This question was taken up by modern philosophers of science and we will look at the two most influential ones, Karl Popper and Thomas Kuhn next time.
Questions
1. Do you prefer induction or deduction when trying to understand something new? Why?
2. Is the mind part of the problem or part of the solution?
3. Is there a proper ratio, or proper time to use each method?
4. If we try to use Bacon's method when attempting to understand a new natural or social phenomenon, how can we know in advance what information is relevant or irrelevant?
5. If we try to use Descartes method given that all perception takes place within the mind, how do we distinguish what is “really” outside the mind from what is “only” inside and get it right the majority of the time?
6. Can we ever eliminate any of the Idols of the Mind?
7. Is there any truth outside of human perception? If so, can we know it?
© 2008 - 2024, Jeff McLaren