Induction vs. Deduction in Science
The Techniques Involved in Creating a Good Scientific Theory
The "Scientific Method" is often summed up as a choice between two diametrically opposed, yet often coexisting modes of thought: Induction and Deduction
Any attempt to unlock the many mysteries of modern physics, to peel back the onion-like layers of such imposing mysteries as Relativity and Quantum Mechanics, must by way of necessity begin with a look at the Scientific Method.
While every science textbook and scholarly article on the subject seems to have a slightly different take on exactly what constitutes a solid foundation for scientific research, often times it is much more simple to break things down into just a couple of major ideas.
In essence, one may find that the key to the scientific method is the question of which is better; inductive or deductive reasoning. It may sound like a simple question at first, but once one really begins to look at the history of science, it becomes anything but.
Induction
Inductive reasoning is that which on the surface seems to be the best way to go about science. Induction in science has at its heart two of the key elements of the scientific theory: Observation and Experiment.
Induction simply means, at its core, that a theory is based on sound research and observation. A scientist observes something, forms a hypothesis, performs some experiments to verify the hypothesis, then, when all is said and done, creates a theory. Indeed, this seems like the most pure way to perform science.
In his 1919 paper on “Induction and Deduction in Physics” Albert Einstein explained that, though Induction does seem like an important step in science, often events work in an opposite fashion:
The really great progress of natural science arose in a way which is almost diametrically opposed to induction. Intuitive comprehension of the essentials about the large complex facts leads the researcher to construct one of several hypothetical fundamental laws… both the fundamental law (axioms) and the consequences form what we call a theory”… But he (the researcher) does not arrives at his system of thought in a methodical, inductive way, rather he, snuggles to the facts by intuitive choice among the imaginable axiomatic theories.
In this he is saying that the history of natural science has been built on the deductive scientific method.
Conversely, famed Caltech physicist Richard Feynman lauded induction in saying that, “Experiment is the sole judge of scientific ‘truth.’” Surely, Feynman was a believer in deduction as well.
Deduction
The deductive scientific method is, naturally, the polar opposite of the inductive. A scientist begins with a theory (which is generally frowned upon), then performs experiments and observations in order to test that theory. When Einstein first issued the above quote, it was easy to see why deduction was the best way to go about creating theories. As the twentieth century progressed, however, especially with the onset of quantum theory, there actually arose a movement toward the deductive method.
An example of the deductive scientific method in use would be this:
A particle physicist is studying the properties of various subatomic particles. He notices that all of the known particles have a certain characteristic which occur in a certain pattern, but there seems to be one particle missing to make the pattern complete. The physicist thus theorizes the existence of this particle based on no previous experimental knowledge of its existence.
Over the past half century, this method has been utilized many times, and often with very positive results. Suddenly, the deductive method turns out to be far more beneficial than would initially have been presumed.
What Now?
The only true conclusion that one can make from all of this is the following:
While a nice, clean, induction-based scientific method is, in general, preferable in most situations, there are certain instances where deduction might actually prove beneficial. It is a testament, really, to the constantly evolving, growing, and changing face of science, and part of what makes the history of such thinking so very interesting.
References:
Einstein, Albert. “Induction and Deduction in Physics.” 1919
Feynman, Richard. “The Feynman Lectures on Physics.” Addison Wesley. 1963.
