Chapter 13: The Nature of Science


In contrast to the preceding chapters, which examined theories about the natural world, this final chapter will focus not on a scientific understanding of nature but on understanding science itself. Misguided philosophical views about the nature of scientific inquiry have had pernicious social and political consequences, and they have also distorted popular perceptions of the relationship between science and Christianity. For these reasons, a discerning view of science is vital for Christians in our present cultural context. This chapter offers a brief introduction to several important topics in the philosophy of science, highlighting issues relevant to creationism, intelligent design, and other subjects of special interest to Christians.

Many people, including some Christians, think that science and faith are incompatible because, supposedly, science and faith involve opposite attitudes toward evidence: science follows the evidence wherever it leads, whereas faith stands its ground no matter what the evidence might suggest. However, this popular allegation is mistaken on both counts:

  1. Science doesn’t just follow evidence wherever it leads. That’s a misrepresentation of how science works; and, as we’ll see, it misconstrues the role of evidence too.
  2. Moreover, having faith doesn’t mean ignoring evidence. Faith usually is based on evidence. Our faith in God, especially, can and should be based on the abundant evidence He has provided of His faithfulness and His trustworthiness.

For further discussion of the biblical concept of faith, see the appendix on The Rationality of Faith. In the present chapter, we’ll carefully consider the nature of science—what science is, and how it works. This will equip you to combat those misapprehensions and see clearly the harmony between science and our faith.

We’ll begin with some introductory remarks about the philosophy of science and the history of the word science. Then, we’ll survey a series of historical attempts to answer the deceptively simple question we encountered in Chapter 1: what is science, exactly? The demarcation problem—the difficulty of formulating a precise definition of science—remains unresolved, but failed attempts to define the essential characteristics of science have illuminated some important features of scientific methodology, which will take center stage in a subsequent section of this chapter. A brief history of the demarcation problem will also broach questions to be addressed later in the chapter, including questions about scientific evidence, scientific explanation, and the objectivity and logical characteristics of scientific reasoning. All of these themes interweave with the demarcation problem, so a historical survey of demarcation efforts will prelude our examination of other important issues in the philosophy of science.

The Philosophy of Science

The most influential proposals regarding demarcation, scientific methodology, scientific explanation, scientific objectivity, and other topics of this chapter have come from philosophers rather than scientists. The reason is straightforward: questions about the nature of science itself are philosophical questions, not scientific questions. As Christian philosopher of science J. P. Moreland observes:

Now the question of how to define science is clearly a topic for philosophers and historians of science. This is not to say that scientists and others cannot be a part of this discussion. It is merely to affirm that, when they participate, they will be largely dealing with philosophical issues for which they are not professionally trained. The fact that these issues are philosophical and not primarily scientific can be seen from the following: Read the relevant debates and discussions and ask what scientific experiment, what scientific procedure, one would use to resolve the dispute. Or get any college catalog and look at the course descriptions in different branches of science. You will discover that almost nowhere in an undergraduate or graduate program in any branch of science are topics such as the definition of science discussed, except perhaps in the first week of freshman chemistry. By contrast, entire graduate study programs in the history or philosophy of science are devoted to definitions of science and to drawing lines of demarcation between science and other fields.J. P. Moreland, Scientism and Secularism: Learning to Respond to a Dangerous Ideology (Wheaton: Crossway, 2018), 122-123.

Philosophy often functions as a second-order discipline—that is, an academic discipline that studies other disciplines. The philosophy of history examines the methods and assumptions historians use in their research, for example; the philosophy of economics examines the foundational assumptions and methodologies economists employ, and so on. For practically any other discipline X, there is a philosophy of X. (There even is such a thing as the philosophy of philosophy, which critically examines the assumptions and methods philosophers employ in our own discipline.) The philosophy of science is a second-order discipline that critically examines the methods, aims, assumptions, and other characteristic features of the sciences. Whereas scientists study nature, philosophers of science examine the nature of science itself.

History and sociology can function as second-order disciplines in a similar way. The fields of study called history of science and sociology of science both overlap with the philosophy of science to significant degrees, and philosophers of science have drawn important insights from both of those fields. However, history and sociology tend to be descriptive rather than prescriptive: historians and sociologists describe what scientists do and how scientific communities operate, but they usually avoid making normative judgments about how scientists should reason or how scientific disputes ought to be adjudicated. In contrast, philosophers critically examine and evaluate the merits of ideas, concepts, methods, and assumptions. Questions about the appropriateness of a conceptual demarcation, about the assumptions underpinning scientific methodologies, and about the reasoning involved in scientific inquiry and scientific explanation, lie squarely within the domain of the philosophy of science.

To understand the nature of science, broad familiarity with diverse natural sciences and especially knowledge of the history of science are essential. That is why I have reserved an introduction to the philosophy of science for the final chapter of this book. Building upon our historically-informed survey of the natural sciences in the preceding chapters, we are—at last—in a position to examine philosophical perspectives about the nature of science itself.

The Word ‘Science’

portrait of William Whewell
William WhewellThis 19th-century portrait of William Whewell is in the public domain. Image source:
1794 - 1866

At the outset, an etymological caveat is in order. The history of the demarcation problem is complicated by the fact that the word ‘science’ did not always mean what it means today. The English word ‘science’ comes from the Latin word scientia, which means knowledge. Less than two centuries ago, both the Latin word and its English derivative were widely used in reference to the collective knowledge accrued in any academic discipline. History, mathematics, and theology were considered sciences—categories of knowledge. People spoke of the science of history, the science of mathematics, the science of theology, and so on. The word ‘science’ did not connote anything like the study of nature or the testing of hypotheses.

From the time of the scientific revolution until the middle of the 19th century, careful study of the workings of nature was called natural philosophy, and those who undertook such investigation—people like Galileo, Boyle, and Newton—were called natural philosophers rather than scientists. Similarly, until the late 1800s, those who studied fossils and geological evidence about the distant past were called natural historians or simply naturalists. The word ‘scientist’ first appeared in print in 1834, coined by Anglican priest and polymath William Whewell, and it gained widespread usage only gradually thereafter.For further details about the history of the words ‘science’ and ‘scientist,’ see this 1962 essay by Sydney Ross.

However, as the label ‘scientist’ rose in popularity during the second half of the 19th century, the word ‘science’ likewise approached its current meaning: increasingly, the word was restricted to the specific fields of inquiry we classify as sciences today. Some thinkers resisted this linguistic trend, fearing that the narrowing usage of ‘science’ would misleadingly insinuate that only fields included within that label could yield genuine knowledge. In a lecture delivered at Oxford in 1872, English philosopher John Ruskin complained:

It has become the permitted fashion among modern mathematicians, chemists, and apothecaries, to call themselves ‘scientific men,’ as opposed to theologians, poets, and artists. They know their sphere to be a separate one; but their ridiculous notion of its being a peculiarly scientific one ought not to be allowed in our Universities. There is a science of Morals, a science of History, a science of Grammar, a science of Music, and a science of Painting; and all these are quite beyond comparison higher fields for human intellect, and require accuracies of intenser observation, than either chemistry, electricity, or geology.John Ruskin, Ariadne Florentina, Lecture V (1872). Available online here.

Ruskin’s misgivings notwithstanding, the word ‘science’ continued its trend toward narrower usage (even mathematics was soon excluded), and by the early 20th century the new jargon had all but replaced the term ‘natural philosophy.’

Despite these terminological differences, though, we can discern throughout the history of Western civilization a series of attempts to demarcate the careful study of nature—what we now call natural science—from other disciplines and fields of inquiry. To avoid confusion, I will use our contemporary terminology in what follows. However, readers should bear in mind that I am using words like ‘science’ and ‘scientific’ anachronistically when discussing the history of the demarcation problem prior to the 20th century. Thus, when I mention “science” and “scientific methods” in earlier periods of history, I am using these words in the contemporary sense, meaning what would have been called natural philosophy back then.