Science, Metaphysics, and Worldviews

James Stump
Boston University

James Stump is a Ph.D. candidate at Boston University in Philosophy. He has an M.A. in philosophy from Northern Illinois University.

In his book, On the Revolutions of the Heavenly Spheres, Nicholas Copernicus says,

In the center of all rests the sun. For who would place this lamp of a very beautiful temple in another or better place than this wherefrom it can illuminate everything at the same time? As a matter of fact, not unhappily do some call it the lantern; others, the mind and still others the pilot of the world, [a visible god, and that which gazes upon all things]. And so the sun, as if resting on a kingly throne, governs the family of stars which wheel around. Moreover, the Earth is by no means cheated of the services of the moon; but, as Aristotle says...the earth has the closest kinship with the moon. The Earth moreover is fertilized by the sun and conceives offspring every year. (Book I, sec. 10)

This is not exactly the kind of argument we expect to find in the book whose publication date defines the rise of modern science. Of course Copernicus also employs empirical data in arguing for his position, but in the end, his new theory did not fit the available data any better than the Ptolemaic theory did. What is it then that allowed him to make his bold shift to the heliocentric universe? And what role did such metaphysical speculations play in the development of scientific theory? It is in discussing these questions that I offer my answer to the topic of this conference: What difference does Christianity make in our thought processes?

Briefly, my argument will proceed as follows: Using the case of Copernicus as my paradigm, I will first argue for the premise that the picture one has of his world, the weltanshauen or worldview, is the final controlling factor for thought. I build up my concept of worldview from the inside out: first arguing for the constitutive role of metaphysics in the development of science, and the consequent influence of science on the acceptance of metaphysical principles. I call this the dialectic between science and metaphysics. Then at a second level, I will argue that all beliefs — whether scientific, metaphysical, political, religious, etc. — are interconnected in a web of beliefs which provides the context for the first-level dialectic between them. It is this context that I call a worldview. The deeper level of my dialectic thesis, then, is that the worldview regulates the thought of a person, while at the same time evolving in response to the elaboration of the thought which it regulates.

To round out my argument for this conference, then, I must add the premise that Christianity is a worldview, thus generating the conclusion that Christianity affects one’s thought. In conclusion I will note and briefly discuss three objections to my hypothesis.

I begin the argument in earnest, then, with my first premise which comes from a quote in a book that was highly influential in the developing field of the history of science in the first half of this century: E. A. Burtt’s, The Metaphysical Foundations of Modern Science:

In the last analysis it is the ultimate picture which an age forms of the nature of its world that is its most fundamental possession. It is the final controlling factor in all thinking whatever. (p.17)

The worldview is the "final controlling factor in all thinking whatever". These are strong words. I turn to the history of science for their defense.

A study of the history of physical theory provides ample data for establishing the existence of a dialectical movement between science and metaphysics. The direction of new scientific theories was influenced by and justified by a metaphysical framework that had already been in place. But then with the advance of the wildly successful science, this metaphysical framework underwent revision. This revision, in turn, altered the constraints imposed by metaphysics and allowed for further development in the science — which again affected the metaphysics... and so on. Science and metaphysics are seen to advance hand-in-hand, reciprocally influencing each other. Here I can give only a highly summarized account of this dialectic culled from the situation of Copernicus. A more detailed version brings out in greater relief this intercourse between science and metaphysics, but it can be seen well enough in the following story.

The beginnings of the old system from which Copernicus turned can be found in common sense observation — of which science is only an extension and classification. It seems to us that the earth does not move; rather it is the sun that rises in the east and moves across the sky to where it sets in the west; it is the moon that moves through the night sky on its monthly trek; it is the sphere of fixed stars that moves around us in slightly less time than the sun takes; and it is the planets that wander in their various courses through these stars. It can only be seen as a natural impulse to place an immovable earth in the center of these other moving bodies. Besides, the earth is much too large to be caused to move. It is made of the element of earth which we see always tends to find its natural place down beneath the elements of water, air, and fire; and earth can only be moved and kept away from this natural place with some effort. The heavenly or celestial bodies, then, must be made of a different kind of stuff, of a fifth element (or quintessence). The heavens are the realm of God and perfection. Accordingly, the heavenly bodies must be made of perfect, incorruptible stuff. And they are, as we can plainly see, the perfect shape: spheres. And they must be immutable as God is immutable, incapable of change. The only kind of movement reconcilable with immutability is movement in a perfect circle with uniform speed; thus there is no beginning or end or change to the movement.

Here we begin to see the dialectic of which I spoke: we start with common sense observations (or rudimentary science), and from these observations possible explanations are posited; such explanations are not directly testable themselves, but they seem to be corroborated by other observations; thus they become established metaphysical principles which constrain further inquiry. A few of the more significant principles that became canonized in ancient and medieval times were:

  1. The earth is stationary and at the center of the universe.
  2. Heavenly bodies are perfect: they are spheres, move only in circles, and at uniform speeds.
  3. There is thus a qualitative distinction between the bodies and the governing laws in the celestial realm vs. the bodies and laws in the terrestrial realm.

Let us continue the story and watch how these metaphysical principles are used and altered in the dialectic with science.

The metaphysical principles constrained any possible further scientific developments as follows: More careful observation of the heavens led to more precise plotting of the paths of the planets as they wandered in their irregular paths through the fixed stars. But while the movements appear irregular, we can be assured that this is an illusion because these are perfect celestial bodies — otherwise, if they were made of the corruptible element earth, they would fall to the center of the universe or be whirled apart in their rapid motions. The precise science of epicycles was developed, then, to save the phenomenon by demonstrating how these seemingly irregular movements can be resolved into combinations of perfectly circular motions. Briefly epicycles were used as follows:

The simplistic version of the ancient picture of the world, in which the planets moved in perfect circles around the earth, could not account for the times when a planet appeared to pause or even move in reverse in its circular orbit through the stars. As early as the fourth century BC it was demonstrated how the irregular movements of the planets could be represented by a combination of different circles: a second moving circle is posited which has its center on the first moving circle. The planet then rides on this second circle, or epicycle. Using the right combination of size and speed of rotation for the epicycle, from the perspective of the observer on earth, it could be seen how the planet would seem to stop and reverse its course, all the while moving continuously in circles at a uniform speed. The phenomenon was saved and the metaphysical principles were still intact.

But because of greater precision in astronomical observation, this science became increasingly complex by the time of Ptolemy in the 2nd century AD. Epicycles riding on epicycles had to be added. They ended up with a system of some 80 separate circles to account for the motion of the sun, moon, and five planets around the earth. Another mathematical device, called the equant, had to be added to account for the observed non-uniform speed of the planets. This was a point outside the center of the main circle with reference to which the planets were supposed to move with uniform speed (rather than with reference to the earth). Through such contrivances the medievals were able to construct a very precise and reliable system for predicting the motions of the heavenly bodies. But the system was monstrous. The influence that the metaphysics exercised on the development of science here is unmistakable.

It was the violation of uniform speed that offended Copernicus the most in this system. So, upon discovering that a 4th century BC Greek, Aristarchus, had postulated that the sun was the center of the universe and that all revolved around it against the backdrop of a fixed sphere of stars, Copernicus set to work on such a system to see if he could explain celestial phenomena more simply and without violating the metaphysical dogma of uniform speed. He showed how the apparent retrograde movement of the planets could be explained by making the planets orbit the sun and putting the observer’s point, our earth, in orbit also around the sun in between the orbits of Venus and Mars. Using essentially the same astronomical instruments and tables as Ptolemy did 1300 years prior, Copernicus constructed this new, simpler system and seemingly overhauled the old.

But consider the ways in which Copernicus was still deeply entrenched in the old metaphysical system. He had rejected the use of the equant because it seemed to him as cheating or sleight of hand in getting around the requirement that perfect bodies must move with uniform speed with regard to their centers. Because of this, Copernicus still had to employ systems of epicycles to account for the apparent non-uniform movement. Furthermore, he had to use another device, the eccentric, to account for the actually elliptical orbits because he would only use circles. In the end, without increasing the predictive power over the Ptolemaic system, he could claim only to have reduced the number of circles needed from 80 to 34. He provided a marginally less complicated geometry of the heavens, but in so doing he raised many new questions and made nonsense of many of the explanations that had worked before. Consider some of the new problems his system generated.

First there were a couple of physical implications that his critics correctly noted: the planet Venus, since its orbit was postulated to lie between the earth’s and the stationary sun, should show phases like the moon shows phases. Also, because the earth moves in space, the appearance of the fixed stars should change with our perspective on them as we move from one side of the sun to the other; this is called stellar parallax. Copernicus could only claim that we can’t see these things well enough to be able to detect them. He was right of course: soon Galileo’s telescope would show the phases of Venus, and in the 1800’s we finally had powerful enough instruments to detect stellar parallax. But his solution was hardly justifiable by the evidence he had, and it could only sound ad hoc to his critics.

Copernicus offered even less satisfactory answers to a second class of objections. One of them was: Why is there not a tremendous wind caused by the daily rotation of the earth? Copernicus could only offer an answer within the old metaphysical system that he still largely espoused: he said that the air must partake slightly of the earthy element and so revolve in sympathy with it. But why does the earth rotate? Well, it is of the nature of all earthy matter to collect together into a sphere, and it is of the nature of a sphere to rotate. He thought if you take any sphere and place it in space, it would of its own accord begin to rotate.

Copernicus’ answer to another objection illustrates my thesis precisely. Why doesn’t the earth doesn’t whirl apart if it is rotating and flying through space in a circle at the kind of speed demanded by the system? First, Copernicus tried again to justify his theory within the older framework of accepted metaphysical principles. He argued that evil effects could not follow from natural movement; since rotation is the natural movement of spheres, it could never have the effect of destroying the nature of that body. But somewhat frustrated by not being able to convince his critics, he in turn asked them why on their system the stars and the heavens don’t whirl apart when they fly through space. In this somewhat rhetorical move by Copernicus, we see perhaps his greatest advance. For it is here that he intimates that the physics of the terrestrial and celestial realms needs to be accounted for by one and the same set of laws. He could not do it yet as he was still working largely within Aristotelian physics and metaphysics, but we see in him an advancement in scientific theory and the consequent development of metaphysical principles.

Of the three important metaphysical principles I listed earlier, Copernicus’ theory violated two of them. At first this was evidence against the theory, but the theory came to be accepted in spite of these violations, and consequently altered the metaphysical framework. This illustrates the second direction of movement of my dialectic: not only is the range of acceptable scientific explanations constrained by the metaphysics, but also, the range of accepted metaphysical principles is constrained by successful science.

The question to which we must now turn for understanding the concept of worldviews is, "Why would Copernicus and his followers accept this new system and its implications while his critics would not?" Because of the different sets of metaphysical principles accepted, we can highlight in the "whirling" debate alternative pairs of internally consistent beliefs: Copernicus’ critics thought the heavenly bodies were made of a different element than earth; and therefore they would not whirl apart when rotating like the earth would. Copernicus postulated that the heavenly bodies and the earthly bodies were made of the same kind of stuff, so both would behave similarly when rotating.

These pairs of beliefs point on a small scale to a central feature of belief systems as I understand them: the interconnectedness of our beliefs. To use Quine’s web metaphor, all our beliefs are connected and mutually dependent on one another. Because of this interconnectedness, revisions in one part of the web necessitate revisions in other parts. When Copernicus made the earth move through space, he had to revise some of the accepted metaphysical principles in order to accommodate this new belief. Also, some beliefs are more firmly held than others. These we can say lie metaphorically closer to the center of the web where there are more beliefs depending on them. Also, beliefs cannot be isolated and tested against experience individually. Rather, the web confronts experience as a whole. Furthermore, the beliefs gained directly from experience must be weighed against the background of the more firmly held beliefs at the core of the web and interpreted accordingly. E.g., even though experience testifies that planets move irregularly, if there is a core belief that they cannot do so, those movements are resolved into combinations of acceptable movements. So the web functions not only as a framework for existing beliefs, but also as a kind of filter through which experience must pass.

There is thus a wider context in place and presupposed by any belief we hold. It is this context, and the core beliefs of the web in particular, that forms what I call a worldview. My first premise then, that a worldview regulates thought, can be seen. Any new belief that I wish to entertain must pass the test of conforming to my context of beliefs. If it is not consistent with this, then I must reject it. Or alternatively, as Copernicus did, I could reject enough of that context so the new belief will not be inconsistent with it. It is the revolutionary periods in science, then, that are characterized by the rejection of large or central portions of this web, rather than rejecting the new beliefs.

So, what was it about Copernicus’ worldview that caused him to reject the Ptolemaic system and some of its metaphysics and embrace a different model of the heavens? Very briefly, consider some of the influences on his thought that could have lent themselves toward this end:

The shift from the earth to the sun as the center of the universe was perhaps foreshadowed and made more plausible by similarly radical shifts that had recently taken place: the commercial revolution in trade with far away lands and even the circumnavigation of the globe greatly enlarged man’s picture of the world. No longer could he blindly assume that the Mediterranean region was the center of all human affairs. Also, through the Protestant reformation and its prior developments, the center of religious authority had shifted from Rome to France and ultimately to individuals.

But we must highlight as most important for Copernicus, the availability of an alternative framework besides the Aristotelian. The rise to dominance of Aristotle in the 13th century surpassed, but did not obliterate the syncretism of Plato and Christianity which had been so important in the first few centuries AD. Especially the Pythagorean variety of Platonism was crucial for Copernicus. This included the importance of numbers and of the exact match between mathematical descriptions and the real world. So since Copernicus’ system was mathematically simpler, it made sense that this system was in fact the way the world really was. For an Aristotelian, logic — not mathematics — is the key to the highest knowledge. To set aside a whole worldview because of mathematics would be absurd. For the Platonist, though, it was a natural step. The transformation to the new worldview was for him largely a mathematical reduction. It is significant to note that for the first few decades after Copernicus, it was primarily the mathematicians that were convinced of the new theory. These influences on the thought of Copernicus can be seen to provide a guiding context of thought in which the heliocentric universe made sense. Lacking these, especially the Pythagorean framework, his critics could not view this move as rational.

Notice now that one of characteristics of a worldview as I have defined it is its capacity for developing itself. It is not the case that a worldview is a static collection of beliefs about the nature of the world and our place in it. Rather, because the worldview comes from that web of interconnected beliefs, it changes with the alteration of those beliefs. When the beliefs towards the periphery of the web change, this does not necessarily affect the core beliefs and consequently the worldview. But for core, worldview-defining beliefs such as the centrality of the earth, or age of the universe, or the constancy of the speed of light in all frameworks, if these are caused to be revised, then the worldview, that set of beliefs against which other beliefs are accepted and held to be rational, is caused to shift. With such a shift, then, there is a different range of acceptable beliefs that can be accommodated by the web.

I have argued so far that a worldview regulates one’s thought. To conclude that Christianity regulates one’s thought, I must add to my argument the premise that Christianity is a worldview. I think for the majority of Christians, this is relatively uncontroversial. The Christian faith for them comprises many of their most cherished and firmly held beliefs, and thus the range of theories that can be accepted, whether scientific, philosophical, or other, is constrained by these beliefs.

A good gage to use in testing how firmly a belief is held is the kind of evidence it would take to give up that belief. What would it take for a Christian to give up beliefs like Jesus is the son of God? If a story were printed on the front page of the New York Times that it has been discovered and confirmed that Jesus was not really the son of God, you would cease to believe in the credibility of the New York Times. If a group of archeologists claimed that they discovered Christ’s bones, thus proving that he did not resurrect from the dead, you would question the reliability of this group of archeologists. In short, almost anything that could be posited as contradicting the central claims of Christianity would be explained away so that the core beliefs could be held.

Accordingly, even experience is interpreted in light of these beliefs. The splendor of these mountains around us here in Colorado is evidence of God’s handiwork. Instances of loved ones recovering from sickness are answers to prayer. Instances of loved ones failing to recover in spite of prayers are interpreted as the hidden will of God.

Do these examples mean that our faith is unfalsifiable? Not necessarily any more than the theory of evolution is unfalsifiable for its ardent adherents. In both cases there is a set of beliefs that can be held come-what-may by revisions in other parts of the web. It is in this sense that I claim that Christianity regulates one’s thought: there is a central core of beliefs resistant to revision, and so other beliefs must be made consistent with these. But still, there are converts into and out of Christianity (and evolutionary theory). No theory is completely immune from revision. The anomalies — be they intellectual or emotional — can mount up to a critical mass and effect sweeping changes throughout the web.

At this point, objections concerning circularity, objectivity, and self-referential incoherence may be suggested. First, two central features of my description of worldviews seem to involve me in a circle: all thinking is regulated by a worldview, and worldviews evolve in response to that regulated thinking. This sounds like a viciously circular affair. It must be asked how it is even possible that a worldview could evolve under the conditions as I have given them: Would not the regulative function of a worldview disallow any anomalous information to enter that would question or alter part of the worldview itself? I believe the reason that this is not the case must be that the regulative function of the worldview is not complete. Worldviews do not completely determine the thought that takes place under them, but rather they only govern or constrain that thought. This is parallel to the role of metaphysics in the first level of the dialectic. Science is not somehow deduced from the metaphysical principles, so too the thought issuing from a particular worldview is not deduced from it. Hence, though being guided by a worldview, there is always an openness to the system of thought and this allows for development to take place. As I understand the process then, it is not a circle, but rather a kind of spiral that takes place. Theories are presupposed which constrain the kind of observations and evidence that is gathered; but the weight of certain evidence and the holes in the theory can sometimes allow for those presuppositions to be altered, which in turn allows for slightly different kinds of observation and evidence, etc.

A second objection to my theory deals with objectivity. If all thought is regulated by one’s worldview, to what extent can we claim objectivity in our beliefs? Where are the objective reference points from which we can judge? Put in another way, how can we know that we are correct in our beliefs? My position forces me to admit that there are no such objective reference points if these are meant to be pre-theoretic observations or thinking that is done under the influence of no worldview at all. But I do not think this admission must lead to relativism. Consider the case of the development of science. In retrospect we can see a clear direction in the development of worldview disputes there: Copernican over Ptolemaic, Newtonian over Aristotelian, the electromagnetic over the mechanical. There is something going on here besides a whimsical preference of one way of thinking to another. Can we say then that even if these theories do not match objective reality itself we are at least getting closer to the objectively true picture of reality? We cannot but feel that we know more about this ultimate underlying reality than did Aristotle or Ptolemy, but can we prove this in a non-circular way, i.e., without assuming the superiority of our own worldview? Ultimately I cannot claim to be able to demonstrate that our theories are closer to the truth than their predecessors — this would require the direct comparison with objective reality that I have deemed impossible. But I do claim that it is plausible to believe that scientific theories on the whole are getting closer to the truth. A fruitful comparison here is found in William Alston’s work on the reliability of sense perception. We cannot prove that our sense perception is a reliable guide to information about the world without in some way assuming that it is reliable. But this inherent epistemic circularity does not prohibit us from feeling strongly that it is reliable, and it certainly does not mean that it is not reliable. It only means that we can’t prove that it is reliable. So too our inability to prove that our theories better portray some objective reality than our predecessors’ do does not mean that they really aren’t better in this way.

Finally, to be consistent, I must admit that my thought too, even in the present examination of worldviews, has been guided and regulated by my own worldview. An objection will be raised, then, concerning the applicability of my analysis to those outside of my own worldview or perspective. That is, in admitting the role that my worldview plays in my study and analysis here, have I limited the validity of my conclusions to only those who share my worldview? Or, have I separated intellectual activity into different, incommensurable post-modern islands and put myself on one of them?

I think the answer to this question is ‘no’. To answer ‘yes’ misses the central point of my thesis, viz., that this worldview is not arbitrarily chosen, but is itself the product of the dialectic that has preceded it. If worldviews were arbitrarily chosen and maintained, my admitting that all I do is regulated by a worldview would have grave implications for the applicability of my perspective outside of my own worldview. But since I have argued that this worldview itself is a dynamic structure that evolves in response to criticism and examination, it can enter into cross-perspectival dialogue with others; it can make value judgments; it can claim to have correct answers — though of course all these are done from within the perspective of one’s worldview, and so are not capable of irrefutable proof. But this does not mean that such worldview-laden conclusions are wrong; it means that they are not final, that they must be critically examined, that they are capable of development.

In conclusion, then, our Christianity does come to bear in our thought processes. It forms a central part of our worldview and is an organizing principle of experience. But again, this commitment is not free from critical examination or development itself. Indeed it is a task of the utmost importance for the intellectual Christian to develop and to show the consistency of a Christian worldview which can dialogue with modern science and which reflects the timeless, absolute truths of the Gospel in our unique culture and generation.