Normal science does not aim at novelties of fact or theory and, when successful, finds none.

It was Thomas Kuhn, the esteemed science expert, who popularized the concept of a paradigm shift in 1962 through his much-respected book, 'The Structure of Scientific Revolutions'. According to Kuhn, a paradigm shift was a change in the assumptions or the theories that science was based on. A paradigm shift was thus contrary to the work of scientists in the specified basic framework, or what he called normal science. Paradigm shifts were not just different from normal science, but they were better changes that resulted in progress as well as a different manner of perception. Kuhn strongly felt that advancement of science could not just be evolutionary, but was actually "a series of peaceful interludes punctuated by intellectually violent revolutions.", where the conceptualized view of the world was peacefully replaced by another, better one. Thus, we can say that a paradigm shift is a change, a metamorphosis in thinking from one point of view, to another. In his book, Kuhn used an optical illusion to show how the same information could be viewed from two completely different points of view.

Thomas Kuhn felt that a paradigm shift occurs when a scientist stumbles upon information or observations that cannot be identified and explained by the ruling theory or the accepted paradigm of science at the time. During such an instance, scientists either ignore or accept the new information or observations as factual errors. However, with time, if more and more observations that cannot be explained by the existing scientific paradigm arise, the existing paradigm is inevitably challenged and experiences a 'crisis'. To overcome the crisis, newer ideas, observations, and assumptions are tried. At such times, older discarded assumptions which were earlier considered to be errors are tried too. This then leads to a new paradigm being formed, one that gains its own advocates as well as critics. Like Kuhn said, it then becomes an intellectual revolution, and a battle between the two paradigms. With time, the new paradigm convinces the community of its validity and reliability as well as the short-comings of the older paradigm. This leads to an eventual shift in thinking in the long run. Once a given field experiences a change in paradigms, it becomes a scientific revolution, a radical metamorphosis.

Though Kuhn always referred to a paradigm shift in the context of the natural and applied sciences, it has been widely used in other disciplines as well. The next section covers a few examples of a paradigm shift in a wide variety of fields, ranging from business to biology to culture to technology. In Culture Culture is one of the most popular areas where we can see not one, but shifts in several paradigms over the centuries. Over the years, what was perceived to be acceptable is abhorred today, while something that was abhorred years ago is considered to be acceptable today. There are several instances of this, such as the acceptance of homosexuality in a lot of the developed cultures today. Homosexuality was unfairly despised and ridiculed till some decades ago, and today, it isn't so anymore. Similarly, slavery, wife-beating, racial discrimination, and child labor were all acceptable in society in the past. Today, not only are they unacceptable, but they are also abolished from society. Though these concepts may exist in some form or the other around the world, efforts are being taken to make sure they disappear entirely. This change in thinking and perception is a shift in the earlier cultural paradigms. In Business The changing nature of business and of the management of business shows a shift in the previous paradigms which specified how business was meant to be done and managed. Along with the advancement in technology and the increased usage of advanced technology in business, organizations today are focusing on how their development can be in sync with the interests of the environment. Business organizations have begun to understand the importance of the natural environment for their own development, and this change in approach is a major paradigm shift from the earlier years when all organizations cared about was profit, and not about the impact their work had on nature. Management has also changed from being mechanical in nature to humanistic, by putting more focus on maintaining a good working environment for the employees so as to inevitably ensure good results for the organization as a whole. In Biology Biology perhaps offers one of the most important paradigm shifts the world has seen― the theory of evolution. Before Charles Darwin and his theory of evolution, it was widely believed that God had created every living species so perfectly that their forms had never changed after they were created. Darwin's theory was radical and supported by evidence. He showed how living beings changed, and how newer species could form from the older ones, and that this was due to natural selection, and not any divine powers. Darwin's theory has changed the way science and the world looks at evolution now. Hence, Darwin brought about a major paradigm shift in biology, which discarded the previous assumptions and theories and progressed with newer ideas. There are other instances in biology that show shifts in paradigms too, such as taxonomy, which classified different species as well as their relationships with one another. In Technology The advancement and breakthroughs in technology are all paradigm shifts that have affected the world for the better. There are several instances to prove this―the introduction of the computer has simplified work for every sphere all over the planet. The shift from using books and encyclopedias for research to using the internet for almost every task is also a major change. Emails and text messages have replaced telegrams and letters as a mode of communication. One recent paradigm shift is the introduction of online shopping. Today, we can buy almost anything online without having to move from our seat. It is not only possible to buy anything from any corner of the world, but it is also possible to pay for it directly, and have it delivered to your doorstep in a few days time. Online shopping is a shift in the paradigm of having to go out to buy something that you want, or need. In Science Kuhn mostly referred to paradigm shifts in the context of science. In the early twentieth century, it was famously declared that the discipline of physics had discovered absolutely everything, and there was nothing new to be discovered, anymore. Physics was ruled by the paradigm of classical mechanics, and scientists felt that this was it, there was nothing more to be found. Thus, when Albert Einstein introduced his theory of special relativity, a few years post this declaration, it challenged the existing paradigm completely, and paved the way for a newer, better one.