2.2: Empiricism and Knowledge

One example from Chapter 1 considered a study that finds an association between a student's race and the severity of school discipline. In this study it is concluded that non-white students face, on average, more severe discipline for the same behavior than white students. Specifically, one of the findings indicates that students from African American and Latino families are more likely than their white peers to receive expulsion or out-of-school suspension as consequences for the same or similar problem behavior. The authors of the research based their conclusions on a review of the documented patterns of office discipline referrals in 364 elementary and middle schools during the 2005–2006 academic year as reported by school personnel (Skiba et al. 2011). The data were modeled using statistical techniques and the authors were able to demonstrate that the conclusions can be inferred from what is contained in the observed data.

For the moment we will not worry about the exact methods that were used to make the conclusions from the observed data. What is important at this time is the fact that the knowledge about this behavior was obtained by directly observing the patterns in society. That is, knowledge was gained from empirical observations. This is an example of empiricism, a philosophical methodology that is closely related to the modern scientific method.

The idea that we can observe the behavior of individuals in society and use those observations to obtain information or knowledge about society is a concept that is taken for granted by most scientists and researchers today. However, the idea that knowledge can be obtained from observation developed over a long time, going all the way back to the classical philosophers of Greece. This development begins with important questions about what is truly known to be true. That is, what is knowledge?

Epistemology refers to the study of knowledge—what separates belief and opinion from things that are known and what we really mean when we say that something is known. Hence, epistemology is concerned with questions that involve concepts such as knowledge, evidence, belief, justification, and likelihood (Fumerton 2009). It is important to note that the word knowledge as used in this context has a very specific meaning that separates it from opinion or belief. Knowledge is very specifically confined to those concepts that are taken to be facts, things that are known to be true. The process of obtaining knowledge is called science.

Definition: Science

Science is the systemic process of obtaining knowledge by deduction and careful observation in the form of testable hypotheses and predictions about the universe (New Websters Dictionary and Thesaurus 1992).

This is a contemporary definition of science that results from over two thousand years of philosophical development. The systematic process used to obtain knowledge is called the scientific method. Philosophers since the time of Aristotle have participated in very deep debates on how a known fact can be distinguished from a belief. The scientific method used today is a relatively recent methodological development and is still the subject of intense debate among philosophers and scientists.

The philosophy of science and the scientific method are generally considered to begin with Aristotle (see Figure \(\PageIndex{1}\)), though he considered philosophy and science to be indistinguishable (Waugh and Ariew 2008). Aristotle saw science as a stable and deductive structure based on first principles (Curd et al. 2014). This view of science is based on an axiomatic framework. That is, a scientific investigation begins with a set of axioms. The axioms are the starting point; they are first principles derived from experience and are known with certainty.

Figure \(\PageIndex{1}\): Aristotle (384–322 BCE) was a Greek philosopher of the classical period in ancient Greece. His methods of inquiry correspond to the first development of the scientific method. He is portrayed here in a Roman marble bust copied from a Greek bronze original. (Public domain image)

Definition: Axiom

An axiom is a statement that is taken to be true and serves as a starting point for further reasoning.

Everything else that is taken to be knowledge is derived from these principles. The key to this method is that the first principles, or axioms, must be absolutely known to be true or the entire system fails.

The axiomatic approach to science depends on making conclusions based on the first principles, or axioms. The method that is used for expanding a theory from the axioms to other conclusions is deduction.

Definition: Deduction

A conclusion is based on deduction if it follows logically from a set of statements that are known to be true.

Essentially, deductive arguments reason that if a statement is true about a group, then the statement is true about any member of the group. For example, we might postulate as an axiom that “all cats are fuzzy.” We may observe that Felix (see Figure \(\PageIndex{2}\)), is quite obviously a cat. We can then deductively conclude that Felix is fuzzy. This is also objectively known to be true as evidenced by the figure. The theory would fail as soon as we observe a hairless cat, which are decidedly not fuzzy.

Figure \(\PageIndex{2}\): Official portrait of Felix Ferdinand Polansky of Creston, IL (public domain image created by the author).

As another example, suppose we want to study rocks using this method. Based on our perhaps limited experience we might postulate an axiom that states “all rocks sink in water.” We might very well assume this to be a universally accepted fact that could not be debated. From this axiom we can then build up a larger scientific theory by deducing facts from this first principle. For example, we might deduce that because all rocks sink, we cannot build a raft from rock. Further development of our rock theory could proceed as usual and in our experience everything about the rock theory might seem to be scientific fact. Everything is fine, that is, until a traveler from a distant land brings us a sample of pumice! Pumice is a volcanic rock that is created when super-heated, highly pressurized rock is violently ejected from a volcano. Pumice has an unusual foamy configuration because of simultaneous rapid cooling and rapid depressurization. Pumice typically has a very low density, less than that of water, and hence a pumice stone will float in water. The problem now is that any part of your scientific theory that depended on the assumption that all rocks float is invalid. In fact, after the explosion of the Krakatoa volcano in 1883, rafts of pumice drifted through the Indian Ocean for up to 20 years (Devantier et al. 1992).

Euclid used this axiomatic method to develop geometry with a great deal of success, though modern research in geometry often challenges some of the axioms that Euclid relied on. Even in this case, standard Euclidean geometry is a valid geometric system for most applications. However, Aristotle's view of science has had some spectacular failures. A prominent example is in describing planetary motion, where the assumptions that postulated all earthly bodies move toward the center of the universe and that planets tend to move in circles around the center of the universe could not withstand observational scrutiny (Curd et al. 2014). Essentially, what was observed empirically did not match what should have been observed had the postulated model been true.

Nicolaus Copernicus formulated a model of the universe that placed the sun, rather than the Earth, at its center, at odds with earlier models that assumed that the Earth was the center of the universe. Though Aristarchus of Samos, an ancient Greek astronomer, had formulated such a model some eighteen centuries earlier, the publication of Copernicus's model in 1543 was a significant advancement in the history of science. Copernicus' ideas triggered the Copernican Revolution, a major reassessment of the nature of science and the universe that through the subsequent work of Galileo, Descartes, and finally Newton, showed that the planets in our solar system revolve in elliptical orbits around the sun.

Galileo Galilei (see Figure \(\PageIndex{3}\)) is widely regarded as the first modern physicist because he was the first to use mathematics to describe the dynamic behavior of moving objects. This was a major shift in scientific methodology since at the time it was thought that mathematics could not be applied to physical reality. Furthermore, Galileo emphasized testing hypotheses experimentally, which at the time was not considered a reliable means of obtaining knowledge. This is the beginning of the empirical approach to scientific investigation (Okasha 2002). The work of Galileo was refined by other scientists, namely René Descartes. Isaac Newton improved Descartes’s theory—and invented calculus along the way—to develop what is known a Newtonian mechanics, a theory that remained essentially unchanged until the early twentieth century and which is the basis for most calculations involving the behavior of physical bodies in motion to this day.

Figure \(\PageIndex{3}\): Galileo Galilei (1564–1642) was an Italian scientist who began the development of the modern scientific method, shown here in a 1636 portrait by Justus Sustermans (public domain image).

For our current discussion, the important aspects of the Copernican Revolution are the effects that its development had on the philosophy of science, and the rapid expansion of scientific thought that occurred roughly between the writings of Copernicus and the synthesis of Newton's model for the universe. It is in this rapid expansion of science that empiricism, the theory that knowledge is gained from experience, became an import idea in scientific thought. By the start of the Copernican Revolution, empiricism had already become an important component of science. For example, the early 14th-century philosopher William of Ockham started an intellectual movement toward empiricism (Hannam 2011).

Definition: Empiricism

Empiricism is the philosophical theory that knowledge is gained through experience.

British empiricism arose from the philosophical differences between Francis Bacon, an empiricist, and René Descartes, a rationalist whose philosophy was closer to that of Aristotle. Thomas Hobbes, George Berkeley, and David Hume were the primary supporters of British empiricism, and collectively they developed a sophisticated empirical framework as the basis of human knowledge.

An influential formulation of British empiricism is based on John Locke's “An Essay Concerning Human Understanding,” which was published in 1689. In this essay he maintains that the only true knowledge that is accessible to the human mind is that which is based on experience. He believed that the human mind was created as a “blank tablet” upon which sensory impressions were recorded, and that knowledge was accumulated through a process of reflection. He wrote:

Let us then suppose the mind to be, as we say, white paper void of all characters, without any ideas. How comes it to be furnished? Whence comes it by that vast store which the busy and boundless fancy of man has painted on it with the most endless variety? Whence has it all the materials of reason and knowledge? To this I answer in one word, from experience; in that all of our knowledge is founded, and from that it ultimately derives itself. Our observation, employed either about external sensible objects, or about the internal operations of our minds perceived and reflected on by ourselves, is that which supplies our understanding with all materials of thinking. These are the two fountains of knowledge, from whence all ideas we have, or can naturally have, do spring. (Locke 1974)

It is interesting to note that Locke anticipated the modern use of probability theory in the attainment of knowledge. In his theory of knowledge, it is suggested that there are two types of knowledge, the type that is known for certain and the type that is not certain but is wise to accept. Their reasoning is that very few things are known for certain and therefore we should act based on the probability that something is true (Russell 2013). That is, we cannot really have true knowledge about facts, only a probable belief. This type of reasoning is an important part of scientific study, particularly in fields like psychology, sociology, political science, biology, medicine, and education. We will discuss probable belief in detail in later chapters. It should be noted that the concept of a “blank slate” dates to Aristotle and was later developed by Stoic philosophers.

The empiricists changed the direction of scientific thought from one that is based solely on logical deduction to one that is based on a mixture of observation and logical deduction. The development of empiricism lead to the modern scientific method commonly used today.