In previous posts, I have argued that science has been excellent at creating predictive models of natural phenomena. From the origins of the universe, to the evolution of life, to chemical reactions, and the building of technological devices, scientists have learned to predict causal sequences and manipulate these causal sequences for the benefit (or occasionally, detriment) of humankind. These models have been stupendous achievements of civilization, and religious texts and institutions simply cannot compete in terms of offering predictive models.

There remains the issue, however, of whether the predictive models of science really explain all that there is to explain. While many are inclined to believe that the models of science explain everything, or at least everything that one needs to know, there are actually some serious disputes even among scientists about what causation is, what a valid explanation is, whether predictive models need to be realistic, and how real are some of the entities scientists study, such as the “laws of nature” and the mathematics that are often part of those laws.

The fundamental issues of causation, explanation, and reality are discussed in detail in a book published in 1954 entitled: The Metaphysical Foundations of Modern Science by Edwin Arthur Burtt. According to Burtt, the birth and growth of modern science came with the development of a new metaphysics, that is, the study of being and existence. Copernicus, Kepler, Galileo, and Newton all played a role in creating this new metaphysics, and it shapes how we view the world to this day.

In order to understand Burtt’s thesis, we need to back up a bit and briefly discuss the state of metaphysics before modern science — that is, medieval metaphysics. The medieval view of the world in the West was based largely on Christianity and the ancient Greek philosophers such as Aristotle, who wrote treatises on both physics and metaphysics.

Aristotle wrote that there were four types of answers to the question “why?” These answers were described by Aristotle as the “four causes,” though it has been argued that the correct translation of the Greek word that Aristotle used is “explanation” rather than “cause.” These are:

(1) Material cause

(2) Formal cause

(3) Efficient (or moving) cause

(4) Final cause

“Material cause” refers to changes that take place as a result of the material that something is made of. If a substance melts at a particular temperature, one can argue that it is the material nature of that substance that causes it to melt at that temperature. (The problem with this kind of explanation is that it is not very deep — one can then ask why a material behaves as it does.)

“Formal cause” refers to the changes that take place in matter because of the form that an object is destined to have. According to Aristotle, all objects share the same matter — it is the arrangement of matter into their proper forms that causes matter to become a rock, a tree, a bird, or a human being. Objects and living things eventually disintegrate and perish, but the forms are eternal, and they shape matter into new objects and living things that replace the old. The idea of formal causation is rooted in Plato’s theory of forms, though Aristotle modified Plato’s theory in a number of ways.

“Efficient cause” refers to the change that takes place when one object impacts another; one object or event is the cause, the other is the effect. A stick hitting a ball, a saw cutting wood, and hydrogen atoms interacting with oxygen atoms to create water are all examples of efficient causes.

“Final cause” refers to the goal, end, or purpose of a thing — the Greek word for goal is “telos.” An acorn grows into an oak tree because that is the goal or telos of an acorn. Likewise, a fertilized human ovum becomes a human being. In nature, birds fly, rain nourishes plants, and the moon orbits the earth, because nature has intended certain ends for certain things. The concept of a “final cause” is intimately related to the “formal cause,” in the sense that the forms tend to provide the ends that matter pursues.

Related to these four causes or explanations is Aristotle’s notion of potentiality and actuality. Before things come into existence, one can say that there is potential; when these things come into existence they are actualized. Hydrogen atoms and oxygen atoms have the potential to become water if they are joined in the right way, but until they are so joined, there is only potential water, not actual water. A block of marble has the potential to become a statue, but it is not actually a statue until a sculptor completes his or her work. A human being is potentially wise if he or she pursues knowledge, but until that pursuit of knowledge is carried out, there is only potentiality and not actuality. The forms and telos of nature are primarily responsible for the transformation of potentiality into actuality.

Two other aspects of the medieval view of metaphysics are worth noting. First, for the medievals, human beings were the center of the universe, the highest end of nature. Stars, planets, trees, animals, chemicals, were lower forms of being than humans and existed for the benefit of humans. Second, God was not merely the first cause of the universe — God was the Supreme Good, the goal or telos to which all creation was drawn in pursuit of its final goals and perfection. According to Burtt,

When medieval philosophers thought of what we call the temporal process it was this continuous transformation of potentiality into actuality that they had in mind. . . . God was the One who eternally exists, and ever draws into movement by his perfect beauty all that is potentially the bearer of a higher existence. He is the divine harmony of all goods, conceived as now realized in ideal activity, eternally present, himself unmoved, yet the mover of all change. (Burtt, The Metaphysical Foundations of Modern Science, pp. 94-5)

The rise of modern science, according to Burtt, led to a radical change in humanity’s metaphysical views. A great deal of this change was beneficial, in the sense that it led to predictive models that successfully answered certain questions about natural processes that were previously mysterious. However, as Burtt noted, the new metaphysics of science was also a straitjacket that constricted humanity’s pursuit of knowledge. Some human senses were unjustifiably dismissed as unreliable or deceptive and some types of causation were swept away unnecessarily. How modern science created a new metaphysics that changed humanity’s conception of reality will be discussed in part two.