Science in Christian Perspective



Notes on "Science and the Whole Person -
A Personal Integration of Scientific and Biblical Perspectives

Part 14

Determinism and Free Will
(A) Scientific Description and Human Choice

Department of Materials Science and Engineering
Stanford University
Stanford, California 94305

From: JASA 33 (March 1981): 42-45.

In the previous installment we touched on the nature of scientific descriptions that are cast into a "deterministic" or "chance" mode, where we argued that a Worldview cannot be unambiguously fashioned out of either one of them. We used this argument there to maintain that the issue between Creation and evolution was not properly expressed in terms of a dichotomy between these two forms of scientific description. The issue of determinism and chance, with its alternate forms in determinism vs free will, or God's sovereignty and man's responsibility, deserves further consideration on its own. In a day in which behavioral scientists insist that human choice can be treated within a wholly deterministic framework, while at the same time avant garde scientists insist that the power of the human mind can dominate all of reality in a burst of absolute freedom, it is appropriate-to reflect a little further on the significance of these issues for the Christian scientist who attempts to integrate his scientific perception with his/her Christian faith. In this installment we consider some of the facets of the determinism/free will paradox, and in the following installment we show how the practical consequences of one's conclusions in this area profoundly affect topics related to crime and punishment.

Determinism vs Free Will

The form of the paradox in which determinism is pitted against free will has both a secular and a theological content. In a secular sense the issue is whether a human being is so controlled by his genetic and environmental inputs that his choices flow inevitably from these inputs with any indication of actual choice being nothing more than an internalized illusion, or whether a human being can indeed make responsible choices above and beyond the aspects of fife that form his/her living context. In a theological sense the paradox is well known as the historical Calvinist/Arminian controversy: whether a person's coming to saving faith is the inevitable consequence of God's determining election, or whether a person's coming to faith is an act of free human choice among equally possible alternatives. As usual some attention to the definition and meaning of these two terms is helpful. It is quickly realized that Determinism and Free Will taken in an absolute sense are both idealizations rather than faithful descriptions of reality.

Classical (pre-quantum) physics is often taken as the archtype of determinism; but such strict determinism can be postulated theoretically but never realized experimentally. Consider, for example, a wheel mounted without friction so that it can rotate freely about its axis that passes through its center.1 Its orientation, as described by the angle with respect to a reference direction, changes linearly with time according to the magnitude of the angular velocity. A slight change in the angular frequency introduces a slight change in the reference angle; but no matter how small this change in angular frequency is, we can always wait a sufficiently long time to obtain any value we wish for the reference angle. Thus, regardless of how small the uncertainty is in the angular velocity, as set by initial conditions, the orientation of the wheel itself is completely undetermined if we wait long enough. If such a demonstration can be made within the context of classical physics itself, we have little need of the more dramatic demonstrations from modern quantum physics.

On the other side, no will is ever completely free. There can be no debate but that many choices are not open to us precisely because of our ancestry, our parents' education and financial status, the country and location of our birth, accidents that befell us in growing up, and any of the many other factors that are encompassed by speaking of genetic and environmental determinism. In reality, we find elements of both determinism and "free will" in all aspects.

"Free will" has other limitations, which do not allow a simple analogy with scientific descriptions. "Free will" is an attribute of a human being, indicating the ability to make a significant choice of possible meaningful alternatives. The consequence of modern quantum theory that atomic particles do not have completely deter-mined position and velocity tells us absolutely nothing about the validity of speaking of "free will" as a human action. If this is true, then it is also true that an overturning of modern quantum theory to return to a fully deterministic mechanics would also have no necessary consequence for the significance of "free will" as a human activity.

As mentioned above, the determinism vs free will controversy in a secular sense is the counterpart of the sovereignty of God (predestination) vs responsibility of human beings (human choice) in the theological realm. If it is true that for the Christian, the latter paradox (not a contradiction) is responded to by holding both facets in tension, recognizing that they address different questions in different contexts, perhaps a clue can be obtained from the theological to guide a response to the secular dilemma.

In quantum physics a deterministic description can be given if the variables involved are probability distributions and not "particle" positions and velocities; if it is insisted that particle positions and velocities must be discussed as the variables, only an indeterministic (chance) description can be given. A scientific "chance" description does not inherently mean "meaningless," but only that scientifically definable causes are not discernible. These two types of description take their place with the position vs velocity, and particle vs wave paradoxical pairs-and all may be considered as examples of complementary descriptions. Complementary descriptions are those that are reliable within a given context, but not apparently reconcilable with each other in general.2 Out of this framework comes another clue as to how to regard the determinism vs free will dilemma.

This continuing series of articles is based on courses given at Stanford University, Fuller Theological Seminarv, Regent College, Menlo Park Presbyterian Church, Foothill Covenant Church and Los Altos Union Presbyterian Church. Previous articles were published as follows. 1. "Science Isn't Everything," March (1976), pp. 33-37. 2. "Science Isn't Nothing," June (1976), pp. 82-87. 3. "The Philosophy and Practice of Science, " September (1976), pp. 127-132. 4. "Pseudo-Science and PseudoTheology. (A) Cult and Occult, " March (1977), pp. 22-28. J. "PseudoScience and Pseudo- Theology. (B) Scientific Theology, " September (1977), pp. 124-129. 6. "Pseudo-Science and Pseudo- Theology. (C) Cosmic Consciousness, " December (1977), pp. 165-174. 7. "Afan Come ofAge?" June (1978), pp. 81-87. 8. "Ethical Guidelines, " September (1978), pp. 134-141. 9. "The Significance of Being Human," March (1979), pp. 37-43. 10. " Human Sexuality. (A) A re Times A'Changing? " June (1979), pp. 106-112. 11. "Human Sexuality. (B) L o ve and Law, " Septem ber (1979), pp. 15 3-15 7, 12. "Creation (A) How Should Genesis Be Interpreted?" March (1980), pp. 34-39. 13. "Creation (B) Understanding Creation and Evolution" September (1980), pp. 174-178.

Both Determinism and Free Will taken in an absolute sense are idealizations rather than faithful descriptions of reality.

It is worthwhile to note that we often use our "free will" in order to become "determined." An example is the use of practice to develop a manual skill such as playing an instrument or typing. Another example is the conscious development of good habits-what after all is a habit, but the development of a determining pattern of behavior? Many biblical exhortations call us to develop patterns of thinking so that we may not be "free" to sin. They emphasize that our choices for mental meditation have a profound effect on our lives. The person who habitually chooses to turn away from God, is eventually hardened in this position so that he/she is no longer able to turn back to God. Many biblical passages speak of the will as bound by sin, so that the human being by nature is not free to choose to be obedient to God.

Redefinitions Within the Human Context

It is probably necessary to redefine the terms "determinism" and "free will" in the context of human activity. Consider the following definitions of human acts: (1) a determined human act is an involuntary act performed out of physical necessity, e.g., knee-jerk reaction, decrease in size of the pupil in a bright light, "flight" instinct when faced with sudden danger; (2) a human act carried out by free will is a voluntary act representing a responsible choice, e.g., whether or not to get up, to lie down, or to steal. This is not to deny that it is possible for a human being to be so conditioned that it becomes very difficult indeed not to steal; given the appropriate conditions this may indeed become "second nature" to the individual. In such a case the realm for "free will" choices has just been greatly reduced from that of a person without this conditioning.

Certainly everyday experience indicates that both types of acts described above occur in every person's life. For a person to be so conditioned that no area of "free will"-i.e., no area of voluntary responsible choice is leftis equivalent to reducing that human being to the condition of an animal or a machine. To be sure such inhumane treatment can occur, but to maintain that its possibility argues for its inevitability or its general applicability to all human activity violates common personal experience.

Scientific Descriptions of Responsibility and Choice

When we ask what type of scientific description is most commensurate with responsible human choice-a deterministic or a chance description-we are faced by a curious paradox. If we define "free will" as a voluntary act representing a responsible choice, i.e., a choice for which we can be meaningfully blamed or praised, then such responsible choices seem to call for an orderly scientific description within the confines of cause and effect. But this is the type of description to which we give the title, "deterministic." It is needed in order that scientific descriptions of the subsystems of the human being may provide the framework for regularity, predictability, order and repeatability-all of which are characteristic of responsible choices in many instances. To invoke a "chance" description, a description in which cause and effect cannot be mechanistically or mathematically related, in order to safeguard the reality of "free will" provides no basis at all for a responsible choice. What responsible choice ever arose from a chaotic, unrelated, and random pattern of activity?

We are therefore led to the following curious paradox: Determinism appears to threaten Free Will philosophically-for how can what is determined be free, but is essential for it-for how can a responsible choice exist without being describable in a cause and effect framework? Similarly Chance appears to make room for Free Will philosophically by removing the constraints of determinism, but renders true responsible choice impossible by reducing the situation to a random, unpredictable and unrepeatable case.

Furthermore it must be remembered that when a large number of individual chance events of the same type are taken together, an apparently deterministic result follows. The average lifetime of my generation is well defined plus or minus a couple of years, but whether any one of us will die tomorrow is virtually unknown. Thus a substratum of chance events at an elementary level can still give rise to deterministic behavior at a more complex level. According to modern quantum mechanics the radioactive decay of a radioactive element is totally a probabilistic (chance) phenomenon; when any particular atom will decay can be described only in terms of probability (no known cause exists), but when half of the ensemble of a large number of atoms will decay is a highly determined and determinable quantity: the half-life of the element.

These examples reveal the danger in assigning ultimate philosophical or metaphysical meaning to the terms of determinism and chance used in scientific descriptions. If the design of the water molecule reveals the necessity for hydrogen and oxygen atoms to exist in one and only one lowest energy relative configuration (the structure is determined), the design of the DNA code reveals an arrangement attributable only to chance in a scientific description since there is no single lowest energy state-else all human beings would be identical. Thus determinism can be the instrument of design, but so can chance; the creativity expressed in the creation of the multiplicity of human beings is expressed scientifically through the chance assignment of DNA configurations.

An Experimental Test

Pursuing this same line of reasoning further we may ask what kind of experimental test or measurement can be made to help decide the determinism/free will dilemma.

One might invoke a kind of Indeterminacy Principle such an experiment, arguing that conditions that make possible to test for determinism or free will so alter the state of the experiment that the original question cannot be meaningfully answered. For example, the test of determinism might involve a large number of electrodes implanted in the human brain so that appropriate sampling of all brain processes can be carried out; since these electrodes must all be hooked up to a detecting apparatus, the experimental subject is hardly free to do much of anything! To put the subject into an ideal environment for free choice would be to separate him/her from all other inputs or influences so as to minimize environmental effects and leave open the basic exercise of free choice; but in that isolated condition an experiment can hardly be carried out.

We often use our "free will" in order to become "'determined. "

One might argue that these are limitations imposed only by existing technology and may be expected to be overcome in the future (the same objections are often leveled against the Heisenberg Indeterminacy Principle in quantum mechanics) by better techniques or the understanding of more fundamental variables. Be that as it may, the question still remains as to what kind of experimental test would settle the question even if these operational problems were abi sent. If a decision is accompanied by a continuous set of phenomena and patterns in the brain waves, thus providing the basis for a deterministic description of decision-making at the biochemical level, should this be interpreted in favor of or opposed to a free choice? If a responsible free choice should not be described within a deterministic framework at the biochemical level, how should it be described? And if a deterministic description of biochemical reactions is consistent with a free choice, how can one claim that free choice is an illusion simply because a deterministic description on the biochemical level is possible?

Indeed one is led by this line of argument to conclude that the ability to present a deterministic description does not help to settle the determinism/ free will paradox, but that the actual experimental finding of a chance situation would enable one to rule out the reality of responsible choices. Here we are again confronted with a usual dilemma. A series of phenomena that can be described scientifically only as chance events at one level of organization frequently manifest themselves as deterministic descriptions at a higher level of organization in which many such chance events participate. Might we not then argue that somehow "free will" expresses itself through the randomness of the lower level and manifests itself through the deterministic properties of the higher level? Experiments revealing chance on the lower (biochemical) level do not therefore necessarily imply that a deterministic description at the level

  Determinism appears to threaten Free Will philosophically, but is essential for it. Chance appears to make room for Free Will but renders it impossible.

of the whole person's decision making is absent. Therefore, once again, the experimental results are ambiguous and the finding of a chance behavior may well be compatible with a person's free choice. 

We may conclude that no scientific experiment seems possible that would enable us to decide between the validity
of an absolute "determinism" and an absolute "free will." Such an outcome suggests that common definitions of these
terms are inappropriate, and that they represent complementary approximations to a more complex whole.

Knowing the Future

If it were possible for someone to know my future, would this in itself constitute a violation of my ability to make free responsible choices? Sometimes people are intimidated by the biblical teaching that God knows the future as though it were present, and argue that if this were true, we would all be automata and fatalism would be the only appropriate philosophy. In order to be free in their perspective,
no one must be able to know the future. Reflection on the question, however, reveals that our freedom to act from within our own context is in no way limited or infringed by the possibility that another person might know the future. In deed it is this weak form of "foreknowledge" that has often been advanced to soften the stronger biblical "predestination" in an attempt to avoid the grips of the stronger predestination/ free will paradox.

A variation of this problem has been treated at some length in several publications by Donald MacKay.3 MacKay
supposes that our brains are totally deterministic and that a person could take information from the present state of a person's brain in order to predict the future state of the brain for that person. MacKay then asks if such a possibility is an infringement upon my freedom to make choices. His answer is in the negative, for he argues that there is no such description of the future that is binding upon me whether I know it or not, or whether I like it or not. The nature of human consciousness is different from that of the planets in their orbits, for example; the occurrence of an eclipse in the future can be predicted with considerable accuracy. Making this information public does not change the situation. In the case of human consciousness, however, to be told the prediction would in itself alter the condition of the brain and render the prediction not something that I would be correct to believe and incorrect to disbelieve. The reader who wishes to pursue all the nuances of this claim is urged to investigate the referenced literature.


Attempts to resolve the determinism vs free will controversy in terms of some neat dichotomy are an illusion. These two aspects of reality are interwoven throughout our entire lives so that they form more the two aspects of one reality, than two competing absolute worldviews.

Attempts to relate the forms of scientific description to the realities of personal life are equally nonproductive. A deterministic scientific description appears most compatible with a responsible human choice, but is commonly believed to make such responsible choice impossible. Relief from determinism through an appeal to chance appears to make other options possible, but a responsible choice is not one of them since it is hardly compatible with random noncaused activity.

Questions dealing with determinism and free will must abandon the question for a general answer, and ask instead: To what extent am I determined while at the same time to what extent am I free? Appropriate areas and interactions for both exist within the context of a meaningful human life.


1I. M. Jauch, Are Quanta Real?, Indiana University Press, Bloomington (1973)
2Paul T. Arveson, "Dialogic: A Systems Approach to Understanding,"
Journal ASA 30, 49 (1978)
3See, for example, Malcolm. A. Jeeves,
The Scientific Enterprise and Christian Faith, Tyndale, London (1969) pp. 148-152. D. M. MacKay, The Clock Work Image, InterVaristy Press, Downers Grove, Illinois (1974); Human Science and Human Dignity, InterVarsity Press, Downers Grove, Illinois (1977); J. A. Cramer and D. M. MacKay, "The Clockwork Image Controversy, " Journal ASA 28, 123 (1976); William Hasker and D. M. MacKay, Christian Scholars Review 8, 130-152 (1978)