Kuhn begins with a definition: “normal science” is the everyday practice of scientific research, an everyday practice that is usually on a single great discovery or idea. Normal science is popularized by the textbooks that hand down this knowledge to future generations.
Though normal science will eventually grow to include many specific beliefs and rules, Kuhn notes here that such science often begins with just one big, transformative idea about how the world works.
Kuhn then discusses the concept of “shared paradigms.” These paradigms emerge with a very specific kind of discovery: first, the discovery must be brand-new and so compelling that multiple groups of scientists rally behind it. Second, the discovery must leave room for further exploration. Out of these initial discoveries spring whole bodies of scientific knowledge and research.
Kuhn’s idea of a shared paradigm quickly gained popularity far beyond people who had read his book. But while the term is often taken to mean complete ideological unity, that is not accurate. Instead, Kuhn argues that scientists in a shared paradigm hold the same basic ideas about the universe, but they might try to fill in different gaps or focus on different areas within the paradigm.
A given scientific field cycles through a variety of these research paradigms; Kuhn gives the example of physics, which moved from a material view of light to a mathematical one. Crucially, however, there is also a time before paradigms for each science. In these pre-paradigm eras, many different scientists argued about what their fields’ basic facts and focuses should be.
If a paradigm allows scientists to specialize and collaborate, pre-paradigm science is all about disagreement. Before a paradigm exists, scientists debate fundamentals; they cannot agree on what questions to ask or what methods to use.
In a pre-paradigm science, scholars cannot build on one another’s work because there is no agreed-upon foundation. However, Kuhn emphasizes that it is important to understand that these early thinkers were equally scientific as their later counterparts. To demonstrate this argument, he cites the field of electricity before Benjamin Franklin.
Because of this disagreement, pre-paradigm science can never get very specific, because scientists are always trying to prove the basics to one another. Yet that does not mean that scientists in a pre-paradigm era are bad at their jobs. Kuhn is careful to note that even scientists who do not attract large followings might have precise techniques and brilliant ideas.
At the same time, there are major challenges to working without a paradigm. First of all, there is so much information available that without a single guiding principle or discovery, it is difficult to make all these facts make sense in the context of a particular scientific field.
Earlier, Kuhn has explained that “arbitrary” beliefs are always a part of science. Here, he clarifies why those beliefs are necessary—without them, scientists do not know where to start their research.
Paradigms then emerge to help scientists focus their attention on certain phenomena and questions. But while successful paradigms are usually more revealing than their competitors, they are never able to explain everything. Instead, they help scientists by allowing them new confidence and specificity. Or as Francis Bacon once put it, “truth emerges more readily from error than from confusion.”
Paradigms provide clear starting points, and so they are immensely useful—but being useful is not the same thing as being accurate. And indeed, this Francis Bacon quote makes clear that what paradigms eliminate is “confusion,” not “error.” In other words, paradigms might bring clarity about how to proceed, but they do not necessarily bring truth.
When a new paradigm becomes popular, the older groups of scientists slowly disappear. Some of these scientists change their beliefs to match up with the paradigm. Others are simply ignored, and they must find new specialties or fields from which to develop their beliefs.
As more and more scientists devote their life to the new paradigm, dissenting views become increasingly frustrating and even threatening. Accordingly, scientists from different groups in the pre-paradigm era are pushed out of the field.
Similarly, as a paradigm develops, the scientists working in it grow increasingly specific in their discoveries. Therefore, scientific literature becomes less and less accessible to regular people. Only in pre-paradigm science does a scientific book have the same kind of audience that a book in any other field would have. Yet Kuhn argues that even if a paradigm makes discoveries narrower and less broadly useful, it is also the very thing that “proclaims a field a science.”
Because scientists in a shared paradigm have a collective knowledge of the basics, all new discoveries are highly specific and based on prior knowledge. Normal scientific research is therefore inaccessible to anyone who lacks that prior knowledge (which is most people). However, this specialization is now viewed as an essential part of science because it is so specialized.