Carl Hempel's deductive-nomological model of scientific explanation

¶ … Science

Philosophy Inherent in Science

Explanation in Science

This summary was a review of Carl G. Hempel's "Explanation In Science," which was reprinted from "Scientific Knowledge" and was edited by Janet A. Kovoany. Carl Hempel was well-known for his scientific explanation concept which has become the foundaton of many modern day philosophical discussions on the purpose and logic of science. Hempel's work was insightful and it was founded on the basis that man uses science to continually improve his current situation or 'strategic position' by either prediciting or controlling events and things around us. Hempel professed that we as a species are impelled to satisfy an inner curiosity and need to explain all that is around us and all that is unexplainable. In my researching Carl Hempel I discovered that his peers saw him as a man who was on the level of Socrates and his true genious can has been demonstrated in his work to develop the Deductive-Nomological (DN) model. Hempel studied at the prestigious Realgymnasium in Berlin, Germany and also attended the University of Gottingen. He taught at Jerusalem, Pittsburgh, Berkley, Yale and Princeton and consistently produced philosophical and scientific papers and other books. Hempel and his friend Paul Oppenheim published many books and papers. Hempel published his "Aspects of scientific explanation" in 1965. Unfortunately, Carl Hempel died in Princeton, New Jersey on November 9, 1997. (Hempel, 1998)

The first argument is that Hempel discussed two basic types of scientific explanation: Deductive and Nomological. Hempel and Oppenheim felt that a scientific explanation of a fact was considered a deduction of a statement called the explanandum which actually describes the fact that we would need to explain. They also defined a premises or explanans which are scientific laws or the initial condition of an experiment. Hempel's theory of science was that for an explanation to be acceptable, the explans must be true. This was Hempel's deductive-nomological explanation. "A good many scientific explanations can be regarded as deductive-nomological in character." (Hempel, 1965)

The second argument is that Hempel theorized that a deductive-nomological model means that an explanation of a fact can be reduced to a logical relationship between statements. In other words, 'the explanandum is a consequence of the explanans' which has become a basic tenet in the modern philosophy of logical positivism. Hempel's explanations need scientific laws or facts.

Hempel theorized that there are two types of laws. The first type is a law which is a universal constant in science such as the law of gravity. These laws are based on the fact that they have not yet been proven wrong and are universally accepted as true all of the time. The second law type would be a statistical probability or a Probabilistic explanation. This type of law can be a statistical probability that can be proven; Hempel used the concept of getting haw fever to explain this type of law. When someone has hay fever, statically it is assumed that is what it is but technically the germs could be a mixture of anything. Yet, we still consider the symptoms as hay fever. Clearly, this explanans does not deductively imply the explanandum; "John Doe's hay fever attack subsided; the truth of the explanans makes the truth of the explanandum not certain, but only more or less likely, or perhaps, practically certain." (Hempel, 1965)

In conclusion, this summary was a review of Carl G. Hempel's "Explanation In Science." Carl Hempel was a well-known scientific philosopher known for his scientific explanation concept. Hempel's work has a foundation that man uses science to continually improve his current situation or 'strategic position.' Hempel beklieved that man has an inner curiosity and this entails that we must try to explain eveything around us. Hempel's Deductive-Nomological (DN) model is his way of explaining how we use science to meet that inner need.

Understanding the Cosmos

Seeking New Laws of Nature

This summary was a review of Richard Feynman "Seeking New Laws of Nature," from "What Does Science Tell Me About the World." Richard Feynman was well-known for his work in theoretical physics and has won the Albert Einstein Award three times as well as the Lawrence Award for achievement and was a Nobel Prize Laureate in Physics for his work with quantum electrodynamics and the deep-ploughing consequences of elementary particles. Even with this strong physics background, Feynman was also considered a great modern day philosophical mind because of his understanding of the purpose and logic of science. The work "Seeking New Laws of Nature" was a part of a verbal lecture that was so impressive that it was later transcribed and sold as a book entitled The Character of Physical Law. The basic idea of the piece is how man creates concepts that eventually become laws of nature. Feynman comes across as having fun with the piece becuase there is a great deal of wit and charm even though these are complicated concepts made to sound very fundamentally easy.

This work was a summary of the state of man's knowledge of our physical world. The story which began as a lecture probed many existing mysteries and thus discussed a viable and very useful methodology for man to continue to seek new laws. Most children would really appreciate Feynman's goal of simplicity because the way to seek new laws of nature is to simply begin guessing. Once the guess is made, however, Feynman uses the time honored methods to develop and analyze the guess that eventually become accepted laws. "In general we look for new law by the following process. First we guess. Then we compare the consequences of the guess to see what would be implied if the law that we guessed is right." (Feynman, YEAR)

Richard P. Feynman was a city boy who was born in May of 1918 and was raised in New York City. His education consisted of a Bachelor of Science from the Massachusetts Institute of Technology and a Masters and Doctorate from Princeton. He did a great deal of work as a research assistant at Princeton, Cornell and eventually became a full fledged professor at the California Institute of Technology. Richard Feynman has written a number of scientific papers and had a New York Times best selling book called "Surely Your Joking Mr. Feynman. Adventures of a Curious Character."

The basic premise of guessing is finding out if those guesses are right or wrong. Feynman believed that figuring out the wrong guess quickly would be the way to go because that way we can create progress. Because laws are conceived by guessing, the first argument is that if we are to prove a guess right or wrong, the guess cannot be vague. "If the guess that you make is poorly expressed and rather vague, and the method that you use for figuring out the consequences is a little vague -- you are not sure, and you say, "I think everything is right because its all due to so and so, and such do this and that more or less, and I can sort of explain how this works ..., " then you see that this theory is good because it cannot be proved wrong. (Feynman, YEAR)

Feynman explains that sometimes experiments and laws are proven even though the guess already occurred and it is now a law. Man, in other words, is trying to resolve if the guess was in fact a law and is therefore experimenting for confirmation. "For example, we may know a great many laws, but we do not know if they work at high energy." (Feynman, YEAR) Thanks to this modern way of thinking, and guessing, we have become free to use our own experiences, our own senses and our own way of thinking to create and understand the laws of our own reality.

In conclusion, this summary was a review of Richard Feynman "Seeking New Laws of Nature," from "What Does Science Tell Me About the World." Even with this strong physics background, Feynman was considered a great modern day philosophical mind. Through his informative lectures and books he helps us understnd the purpose and logic of science. The work "Seeking New Laws of Nature" was a part of a verbal lecture that was so impressive that it was later transcribed and sold as a book entitled "The Character of Physical Law." The basic idea of this article was to show how man creates concepts that become laws of nature.