Empiricism, Sensationalism, Rationalism, & Positivism
As we described in Part 2, science is a distinct type of philosophy. The Renaissance and Enlightenment philosophers who established what we today think of as science are customarily classified by their stance on a few basic, philosophical, perspectives: empiricism, sensationalism, rationalism, and positivism.
Empiricism and sensationalism both refer to the belief that all knowledge comes through the senses. These philosophies are very similar, both stressing that all knowledge enters the mind through the senses. Empiricism was most popular with the British philosophers, and sensationalism with the French.
Empiricists and sensationalists both rejected rationalism, the position established be DesCartes, that argued thinking and the processes of the mind should be the route to knowledge. The distinction between empiricism and rationalism can be blurred. I often like to think of rationalism as information that comes through thinking, whereas empiricism comes through the senses. For example a thought experiment, or speculating about something is rationalism, whereas measuring something and categorizing it is empiricism.
Positivism is a concept that was very popular in early science, and increased in popularity into the 20th century. Positivism places importance on publicly observable events. This ideology was very common with empiricists and sensationalists, who felt that science should focus on measurable and observable experience. Positivism is a strict scientific attitude that holds as the goal of science to establish scientific laws and statements. In the 20th century the ideas of positivism would be challenged by what is sometimes called postpositivism. An extreme form of positivism, one in which the belief is that the only valid or useful form knowledge comes from science is referred to as scientism.
A momentous year for intellectual history, and for the philosophy of science is 1781. In this year, Immanuel Kant published a work entitled Critique of Pure Reason. In this tome of critical philosophy, Kant presented a model of individual thinking that synthesized empiricism and rationalism. Kant described how empirical and rational are both active in experience, in other words, we do not passively record the world, as empiricists would have it, but actively participate in making of the world through perception.
Kant's synthesis resulted in a divisive chasm in philosophy, sometimes called the Kantian split. We can see philosophy taking two different directions in the following 19th century, both claiming lineage back to Kant. One side of this split is called analytic philosophy and is popular in the English speaking world. It prefers logic, mathematics, and empiricism through controlled experimentation. Continental philosophy was mostly popular in the German, French, and Italian cultures, and is skeptical of much of analytic philosophy's claims. The lineage of continental philosophy can be seen from Kant, to G.W.F Hegel, to Karl Marx. Continental philosophers include figures such as Friedrich Nietzsche, the existential philosophers, and Martin Heidegger. Science as we know it today has grown out of analytic philosophy, whereas science criticism grows out of continental philosophy.
It is important to consider what the implications of the Kantian split are for epistemology and the philosophy of science. On one side, the analytic philosophers, we have belief that logic, mathematical models, and method will lead to laws of nature. On the other we find a critique of this, and an emphasis on cultural, social, political, biological, and economic pressures on human knowledge. This might best be illustrated through what is known as the science wars.
As a conclusion to this primer on the history and philosophy of science, I will introduce three different philosophers of science and their take on what science is. These three thinkers might serve as an introduction to the science wars. They are: Karl Popper, Thomas Kuhn, and Paul Feyerabend.
20th Century Science Wars
Karl Popper argued that science starts with a problem. He said that scientific method follows three steps: problem, conjectures, refutations. The emphasis here is that science is a method that is used to arrive at a solution, and that, in time, all theories are found to be false and replaced by improved theories. This is the common impression of what science is to most laypeople. However, it is important to point out that how science is actually done and what people believe about it, is much different than what Popper describes.
Popper proposed that science must limit itself to falsifiability, that is, an idea (hypothesis) must be testable for incorrectness. The hypothesis must make risky predictions that can be incorrect. For Popper, the scientists should be trying to prove their ideas to be wrong, rather than trying to find evidence for their ideas. This is where current practices by scientists run countercurrent to Poppers system. Many scientists today look for evidence to support their hypothesis, rather than disprove it.
Thomas Kuhn published a book in 1962 that revolutionized how we think about science. In The Structures of Scientific Revolutions, Kuhn suggests that science is not a method, but rather a social phenomenon. He claims that science is a product of social, economic, and political pressures that dictate what is studied and how it is studied. Kuhn argued that thought progressed in popular viewpoints of how science should be done, and what it studied, called paradigms. He contended that the history of science is a series of shifting paradigms, based more on who held the positions of power in the scientific community (journal editors, professors, research funding) rather than the scientific findings themselves. Kuhn said that these paradigm shifts in science occur not because of a significant finding, but rather, because old ways of thinking are retired when the people who hold them retire. Kuhn's view of science emphasizes science as a social phenomenon.
Paul Feyerabend was an anarchist thinker. In his 1975 text, Against Method he argues that the only true way to scientific discovery is an "anything goes" approach to thinking. Feyerabend says that the methods and rules that the scientists follow actually discourage and inhibit new discoveries. He points out that all of the major scientific discoveries of the 19th and 20th centuries were made by people who rejected the methods and systems that their peers followed. Feyerabend's works challenge all of the assumptions of Enlightenment thinking and seems poised to make a significant impact on contemporary scientific thought.