Chapter 4 How We Make Sense of Things
Chapter 4
How We Make Sense of Things
Science is about sense-making. The natural sciences try to identify patterns within the natural world and then to seek out the deeper structures which can account for these patterns:
The hallmark of natural philosophy is its stress on intelligibility: it takes natural phenomena and tries to account for them in ways that not only hold together logically, but also rest on ideas and assumptions that seem right, that make sense.1
Michael Polanyi, the Hungarian chemist who later went on to explore the philosophical implications and consequences of the scientific method, neatly summarizes the dynamics of the scientific endeavour: “The pursuit of discovery,” he writes, is “guided by sensing the presence of a hidden reality toward which our clues are pointing.”2
We observe things on the surface of reality and try to work out their deeper structures. The great scientific pioneer Isaac Newton (1643–1727) came to realize that there was a common “hidden reality” lying behind the motions of bodies on earth, such as the falling of an apple from a tree, and the movement of the planets round the sun. Newton called this invisible, intangible, hidden reality “gravity” and was never quite sure that the notion actually made sense. His explanation of things seemed to raise as many questions as it answered. As history records, a gallery of hecklers protested against this idea of an invisible, intangible, unobservable force. But Newton was clear that it seemed to be the best way of explaining what he observed. The existence of gravity is now taken for granted, as part of the furniture of the scientific worldview.
We observe certain things; but what is their meaning? C. S. Lewis famously described things such as the human sense of right and wrong as “clues to the meaning of the universe.” Such “clues” are not hard proofs: they are soft pointers.
Science, therefore, can be thought of as a quest for what Polanyi called “a hidden reality toward which our clues are pointing.” Here the use of the word “clue” is very significant because it points immediately to a degree of uncertainty in our knowledge. We observe certain things; but what is their meaning? C. S. Lewis famously described things such as the human sense of right and wrong as “clues to the meaning of the universe.” Such “clues” are not hard proofs: they are soft pointers. Yet the accumulation of such clues often has an intellectual intensity that transcends the power of some so-called proofs.
Scientific explanation can be thought of as the quest for a “hidden reality,” a deeper structure, which makes sense of our observations and experiences of the world. So how might this “deeper structure” explain anything? Three major understandings of scientific explanation are widely used in the philosophy of science:
We will explore each of these approaches in a little more detail and consider how they illuminate the human quest to make sense of things.
1. Causal Explanation
The most familiar type of explanation is causal. If A causes B, then A explains B. It is an idea that is familiar to everyone. If I throw a hardball at a neighbour’s window and it breaks, then my action is an explanation of why the window broke. Causal explanations play a major role in science. In the debate now raging about global warming, the key question is whether human beings have caused environmental changes through the production of greenhouse gases. If the world is getting warmer, how is this to be explained? Identification of the causes of global warming is essential if the trend is to be checked, let alone reversed.
But what about more difficult questions? For example, how are we to explain the origins of the universe? Was the universe caused by something or someone? The old idea of the eternity of the universe, characteristic of much earlier science, has now generally been abandoned, on account of increasing evidence that the universe had a beginning. The twentieth century saw dramatic changes in our understanding of the origins and development of the universe.6 Its first two decades were dominated by the assumption that the universe was static. Yet during the 1920s, evidence began to emerge suggesting that the universe was indeed expanding. Up to this point, it had been generally (though not universally) assumed that the nebulae observed in the night sky—such as M31 in Andromeda, or M42 in Orion—were part of the Milky Way, the galaxy within which our solar system is located. On the basis of observations at the newly constructed 100-inch telescope at the observatory on Mount Wilson, a peak in the San Gabriel mountains in California, Edwin Hubble (1889–1953) proposed that these objects were galaxies in their own right, lying far beyond our own. By developing work on the spectral redshifts of these galaxies, Hubble was able to propose that the greater the distance between any two galaxies, the greater their relative speed of separation. The universe was expanding, with increasing speed, and apparently irreversibly.
In Hubble’s time, it was a difficult idea to accept since it seemed to suggest that the universe must have evolved from a very dense initial state: in other words, it implied that the universe had a beginning. But this was merely a suggestion, one way of making sense of the observations. Other ways of making sense of astronomical observations were certainly possible. The best known of these was set out in 1948, when Fred Hoyle and others developed a steady state theory of the universe, which held that the universe, although expanding, could not be said to have had a beginning. Matter was thus being continuously created in order to fill in the voids arising from cosmic expansion.
Opinion began to shift in the 1960s, chiefly on account of the discovery of the cosmic background radiation by Arno Penzias and Robert Wilson at the Bell Laboratories in New Jersey.7 They were experiencing some difficulties: irrespective of the direction in which they pointed their antenna, they found that they picked up an unwanted and obtrusive background hissing noise which they simply could not eliminate.
It was only a matter of time before the full significance of this irritating background hiss was appreciated. It could be understood as the “afterglow” of a primal cosmic explosion—a hot big bang—which had been proposed in 1948 by Ralph Alpher and Robert Herman. This thermal radiation corresponded to photons moving about randomly in space, without any discernible source, at a temperature of 2.7 K (on the Kelvin scale). Taken alongside other pieces of evidence, this background radiation points to the inescapable conclusion that the universe had a beginning, and it caused severe difficulties for the rival steady state theory.8
Since then, the basic elements of the standard cosmological model have become clarified and have secured widespread support within the scientific community. Although there remain significant areas of debate, this model is widely agreed to offer the best resonance with observational evidence. The universe is now believed to have originated some 14 billion years ago and to have been expanding and cooling ever since. The standard cosmological model, often referred to as the “big bang,” describes a universe which is not eternal, but which came into being a finite time ago from nothing.9 So what has caused it to appear? Perhaps the cosmos created itself. Perhaps it just happened. Or perhaps it was brought into creation by an agent—such as God. The traditional Christian doctrine of creation from nothing (ex nihilo) has enjoyed a new lease of life as a result of the new insights.10Might the characteristics of the world, such as its ordering, reflect its divine origins? We shall return to consider this point later.
This kind of approach to scientific explanation can easily be used to assert the rationality of the Christian faith, by arguing for the necessity of God as an explanation of the existence of the universe. Many traditional arguments for the existence of God treat God as an agent who intentionally brings about certain phenomena which are observed to take place. The philosopher of religion William Lane Craig, for example, deduces the existence of God in this way, using the following type of argument:
1. We have good reasons, philosophically and scientifically, to believe that the universe is not eternal, but had an absolute beginning.
2. But something cannot come into being out of nothing.
3. Therefore, there must be a transcendent cause of the origin of the universe—which is God.11
Many atheistic cosmologists initially opposed the idea of the big bang, arguing that, if there was a beginning, then there must be a beginner. It was an embarrassing conclusion to have to draw, but the science increasingly seemed to point in that direction.
2. The Best Explanation
The second approach to scientific explanation recognizes that there will always be multiple interpretations of our observations and experiences. But which is the best? Often the evidence is not good enough to allow us to reach a clear and certain decision. Yet this does not mean that we have to throw up our hands in despair and declare that all interpretations are equally good (or bad). Charles Darwin, for example, was aware that his theory of natural selection was only one of several possible explanations of the features of the biological world. His theory faced competition from the “transformist” idea of the gradual development of species over time.12 Yet he still believed that he was justified in declaring that his theory was the best explanation and that it would eventually be shown to be the best explanation.
So how might rival theories be judged? How do we determine which is the best? The core idea here is “empirical adequacy”: the measure of how well a theory accounts for what is actually observed. How well does the theory map onto the world of experience? How good is the fit between theory and observation? The “best” explanation may not be able to account for all our observations. But it ought to be able to account for them to a greater extent, and in a more plausible manner, than its alternatives.
Nor can the “best explanation” always be proved to be right. Often it must be accepted on trust, as the best way of making sense that is available to us. Science is thus about motivated or warranted belief: something that we believe to be true and believe to be justified in believing, while we know that it cannot always be proved. As we noted earlier, Darwin was clear that his theory of natural selection could not be proved. Nevertheless, it remained the best explanation of what was observed, and it deserved to be regarded as correct on that basis. “The change of species cannot be directly proved,” Darwin wrote, so that “the doctrine must sink or swim according as it groups and explains phenomena.”13 In other words, we have to ask how successful a theory is at making sense of the world, while we look over our shoulder at its rivals.
Finally, the “best” explanation may not be the most reasonable or commonsense explanation. Scientists don’t lay down in advance what is reasonable. Time and time again, they have found the natural world to contradict what common sense might have expected or predicted. Science would fail if it were forced to conform to human ideas of rationality. Quantum theory is a classic example of a scientific field which seems to fly in the face of human reason, offering an account of the quantum world which seems totally counterintuitive. “The instinctive question for the scientist to ask is not ‘Is it reasonable?’ as if one knew beforehand the shape that rationality had to take, but ‘What makes you think that might be the case?’“14 Science is about warranted belief, not about rational belief. The history of science is about the recalibration of notions of “rationality” in the light of what was actually discovered about the deeper structure of nature.
3. Explanatory Unification
The third approach to scientific explanation is based on the idea of “unification.” This involves establishing connections between ideas that were once thought to be unrelated, so that they can now be seen as different aspects of the same big picture. A good example of this is found in the writings of the Scottish physicist James Clerk Maxwell (1831–79), who published a unifying theory of electricity and magnetism in 1865. This theory demonstrates that electricity and magnetism are like the two sides of the same coin. The unification of explanation can also be seen in Descartes’s unification of algebra and geometry, Isaac Newton’s unification of terrestrial and celestial theories of motion, and Einstein’s demonstration of the unity of physics. Not all attempts to achieve unification have been successful; to date, for example, the unification of quantum and relativity theory still remains a distant goal.
The famous quest for the “theory of everything” can be seen as another classic example of this approach. This theory, once it is discovered (though some believe it lies beyond our reach), is expected to provide a framework of meaning that will allow every other theory to slot neatly into its allotted place. Unificatory explanation is the search for the big picture, the grand map, which allows everything to be seen in its proper relationship.
On this approach to scientific explanation, the big question concerns the trustworthiness and capaciousness of theoretical panoramas. What theory of reality accounts both for observation on the one hand, and successful theories on the other? How good is it at interweaving and interlocking what we know about the universe? Such a unified understanding of the world will aim to be both economic (making as few assumptions as possible) and extensive (embracing as much as possible of what we know about the world).
These three approaches to scientific understanding are not inconsistent with each other. They clearly overlap at points, even if their emphases are subtly different. It is important, for example, to realize that not all explanations are causal. Furthermore, the process of explanation is often regressive, leading to the question of whether there is an ultimate explanation of all things, or whether there exists an infinite chain of explanations. The quest for a theory of everything or a grand unified theory can be seen as an attempt to offer a comprehensive explanation of explanations, driven by the desire to have as comprehensive and unified an understanding of reality as possible.
Yet in recent years, it has become increasingly clear that science is raising questions which it cannot answer. Questions arise out of the scientific understanding of the world which seem to direct us beyond science itself, pointing towards a deeper level of intelligibility. Is there something beyond science which helps us make sense of both the successes and limits of science? Might there be a deeper order of things, in which the riddles and enigmas of human existence might find their resolution?
This book will explore one answer—an answer beautifully hinted at in a phrase in the writings of the distinguished Canadian philosopher Bernard Lonergan (1904–84): “God is the unrestricted act of understanding, the eternal rapture glimpsed in every Archimedean cry of Eureka.”15 But first, we must consider the recent emergence of a movement that has denied any such notion, almost as a matter of principle: the New Atheism.