Science in Christian Perspective



Vitalism and Developmental Biology*

From: JASA 13 (December 1961): 69-71.

1. Introduction

The recent advances in biochemical genetics is certain to intensify investigation into the chemical basis of development. Experimental embryology has already embraced a biochemical approach and a wedding of the two disciplines at this level is to be expected. The subordinate mechanisms of gene control as they apply to developmental regulation will provide the common ground for this convergence of interest. Science has been notably successful in its mechanistic approach to life processes, and further fundamental breakthroughs in these areas are anticipated in the near future.

Superficially it would certainly appear that the grave of vitalism is more securely sealed with each advancing step that science takes. Yet, to the Christian man of science who is committed to a theistic world view, is the issue as lifeless as one would be led to believe?

Mechanistic philosophy claims that when all physical and chemical phenomena in living matter can be accounted for, no other phenomena will remain. The dogmatic mechanist would predict that all aspects of life at all levels will ultimately be explained entirely in terms of natural law. On the other hand, vitalism is a doctrine of the supernatural. The dogmatic vitalist would maintain that the development and integrity of living organisms in their wholeness is dependent upon an inexplicable life force or vital principle which is beyond physico-chemical analysis.

In the history of biology, vitalism and mechanism have alternated with each other for the last three hundred years. Currently the majority of biologists would consider the controversy as relatively quiescent, largely, because, during the last century, mechanists have been signally successful in interpreting natural events, while the vitalists have been signally unsuccessful. The last vitalist of note in biology was the embryologist-philosopher Hans Driesch. He died in 1941. Embryology has been, and still is for a minority, one of the last strongholds for vitalism. Developmental biology still raises some thought provoking questions and, therefore, is worthy of attention as we endeavor to capture additional insights into the problem as we face it today.

II. The Perspective of Developmental Biology

The extraordinary fact that an egg with little visible organization can develop into an organism with a vast amount of organization has in the past intrigued both the scientist and the philosopher. Herein resides a mystery which has no parallel in other areas of scientific endeavor. The reproductive cell does not yet possess any of the features of the adult. Yet in its allotted time, development will progress relentlessly toward a wholeness perfect in size, shape, form and function. Normally, as the embryologist Paul Weiss states it, there is no over-development, underdevelopment or probing., excursions along the way.

The perfection of wholeness towards which development is directed is not restricted only to the embryonic egg cell. The capacities for regeneration of lost or damaged parts may be most remarkable. We are familiar with this at the cellular and tissue level during the healing process of cut fingers and broken bones. One wonders why the restorative processes normally cease only when repair is complete?

Regeneration processes in the amphibia are highly developed and most intriguing. An excellent example was an experiment performed under the direction of Dr. Charles Thornton of Kenyon College. Both forearms of a salamander larva were amputated; one above the elbow, the other below. The wounds healed; cellular and tissue differentiation occurred from relatively undifferential cells adjacent to the cut surface. Within a month both limbs had completely regenerated and were functional. Again, one wonders what triggered the regenerative process? How is the particular pattern for wholeness achieved without overshooting or undershooting?

**Dr. Frost is Associate Professor of Biology at Westmont College, Santa Barbara, California.

Another example of directed development toward wholeness is seen in the reaggregation of isolated cells from sponges. If a small sponge is forced through the meshwork of bolting silk the entire organization of the sponge is broken up and its tissues are reduced to isolated cells of a variety of types. These cells begin crawling about and forming small aggregates which then organize themselves into new sponges. Each cell type sorts itself out and assumes its proper position to the whole in keeping with its specific properties. The whole process up to the opening of a new osculum takes about three weeks. What are these mechanisms of reconstitution which tend to reproduce organismic wholeness?

This pattern for perfect wholeness -is also seen at the unicellular level. Ac.etabularia is a unicellular. green algae. The mature cell consists of a reproductive cap with petal-like members, a long stalk and a root-like process. The nucleus is usually in the root-like process. Its life cycle takes about three years. Each autumn the stalk dries up to be replaced along with the cap from the persistent root-like structure in the spring. Its regenerative powers have also been studied experimentally. Removal of the cap will result in its regeneration. Furthermore, a single piece of stalk is capable of regenerating both a new cap and root-like structure. Even more fantastic is the fact that this will occur whether the nucleus is present in the regenerating part or not. If it is present, repeated regeneration can occur; if not, the regenerated cell dies in a few months.

The theme of directed development towards wholeness seems to be a general principle which can be found in some degree at all levels of life. How is this developmental control achieved? Will man ever learn how to control these directing forces? To what extent can we fully understand all that is involved?

III. Vitalistic and Mechanistic Explanations of Developmental Control

For the dogmatic vitalist, the integrating and organizational forces which obtain and maintain the wholeness of the living organism do not reside in physiochemical processes, but transcend them. Furthermore, these forces are goal-seeking and goal-directed. In biological development and regeneration the preordained end towards which these forces continuously strive is the wholeness of the organism. Natural processes are subservient to these forces and become the instrumental means by which the developmental goals are achieved. Vitalism then is truly a doctrine of the supernatural. By definition it lies outside of experimental analysis, and rests entirely upon faith. It should be noted, however, that many vitalists have not equated their supernatural force or vital principle with God as we know Him within our theistic framework.

As indicated before, the opposing position is dog matic mechanism. According to this view, to paraphrase Weisz, all of the operations of living matter are governed entirely by natural law and consequently are amenable to experimental analysis. Therefore, the directing forces of development must all reside within the developmental system itself, and furthermore, must consist of physical and chemical events only. Preordained developmental goals would be denied. Natural events are considered to take place sequentially. Cause produces effect and effect becomes new causes as the chain of events is automatically and progressively forged, a result of internal self-direction. In this view natural events are permitted, not made; end states are consequences, not foregone conclusions of beginning states. This is pretty much the secular approach to present day biology as it is presented in our standard textbooks. It is thoroughly mechanistic and causalistic.

IV. Some Current Issues Relative to the Controversy

Current successes in biochemical genetics and developmental biology stem from the ability of man to make mechanistic models which seem to explain some of the most basic processes of reproduction, inheritance and development. A notable landmark in this regard is the Watson-Crick Model for the desoxyribonucleic acid (DNA) molecule. DNA is the nuclear material which contains in chemically coded form all the heredity information necessary for development. Many feel that this advance is the stepping stone not only to a mechanistic explanation of development, but of the origin of life itself. It is interesting to note that a few years ago these areas were considered to be completely beyond the scope of the biological sciences.

A more startling implication has recently received attention in the lay press. Doty and Marmur, two Harvard biochemists, have recently succeeded apparently in unraveling the two strands of DNA molecules and substituting strands from other bacterial species. Through the subsequent process of bacterial transformation they have obtained hybrids. Time Magazine observes that such tinkering with life has frightening possibilities, for there is no reason why chemical hybridization cannot be applied to higher organisms, the highest of which is man. If man is the product of his genes and his environraent and learns how to alter both, to what extent in the future will he be able to control and determine the finished product?

At this juncture it would be wise, however, to divorce our tendency to speculate, from the evidence at hand. Life has not yet been produced in the laboratory. We cannot rule out the possibility that it may be far more complex than anything that man can completely analyze and duplicate. Also, although man can already alter his genetic make-up, he cannot yet control the genetic alterations and their developmental consequences. Here again the matter may be almost infinitely complex. The more we learn, the more we find there is to learn. This is a process that is not too surprising to the theist who sees life, indeed all creation, as an expression of an infinite God. Nevertheless, the tremendous gains that have been made thus far in our understanding of basic life processes rest securely on the mechanistic basis of our scientific method, and future gains of major significance are predicted.

V. The Position of the Christian Biologist

The question may now be raised relative to the position of the Christian man of science as he faces the problems of life and developmental control. Must he be a dogmatic vitalist or mechanist, or is there an alternative position which contains elements of both in their proper reference; a position which has sharply defined boundaries in some aspects, but a degree of flexibility in other areas where a measure of reservation would be in order. We shall want to explore this possibility further.

First of all, in what sense is the Christian biologist a mechanist? The answer is obvious. He must by definition be a thorough going mechanist in an operational sense. He is dedicated to the task of knowing as much of the unknown as can be realized by the scientific method. He is not committed to the thesis, however, that biological life and its development can ultimately be reduced to a scientific expression, although the possibility in a limited sense is not completely excluded either. And, he most certainly is not committed to the conviction that all of reality is amenable to scientific analysis. The realm of science has limitations. It has nothing to say concerning values, moral meaning, purpose, beauty, love, liberty, justice or ultimate truth. These realities are all outside the boundaries of science. It becomes clear, therefore, that the Christian biologist is committed to the mechanistic view in an operational sense only.

What then is his relationship to the principles of vitalism? Vitalism has been characterized as a doctrine of the supernatural. Its context, however, is limited merely to the processes of biological life. The Christian biologist, if he is to be true to the theistic emphasis of Scripture, would demand a much greater dimension for his supernatural views.

His God is a supernatural God.

He enjoys a relationship with Him which is a supernatural relationship. Moreover, he is committed to the Scriptural thesis that his God created in a supernatural way the order of nature. Herein we see His Transcendance. His God, has even a greater dimension than just that of the first or primary cause or link in a subsequent chain of natural events. Such a restricted view borders on Deism. The God of Scripture not only created natural law and its modes of expression, but actively supports, sustains and directs its operation for His own ends and purposes. In other words nature becomes instrumental in the hand of God for His divine pleasure. The order of nature as we now know it had a beginning and according to Scripture will some day have an ending. The reality behind it will continue on.

The Christian man of science has a God which is even greater than this, for He is also the author and finisher of moral and spiritual law as well. He is truly the Alpha and Omega, the world Ground to all of creation in all of its dimensions. It is only in Him that nature takes on real meaning and purpose. God has chosen the setting of nature which includes man to express eternal values. We need only to look to Jesus Christ for a clear and concrete example.

Within this world view every new discovery in science gives to us added understanding into another dimension of God's greatness. As our appreciation of God's greatness increases, so should our understanding of His grace. God's greatness always accents that great gulf that separates a man from His God. It was the Grace of God which spanned this gulf. What greater and nobler incentive could the Christian investigator desire for his scientific endeavors? Such Christian conviction should intensely stimulate any Christian student who is interested in the mysteries of science.

VI. Conclusion

We would conclude, therefore, that the Christian biologist is neither a dogmatic mechanist nor a vague vitalist in the extreme sense in which the terms have sometimes been employed in the past. True, he is a mechanist in an operational sense, as he applies the scientific method to nature, but even such endeavors take on a vital spiritual dimension as they are integrated into his theistic world view of life. In this, his view of the supernatural differs sharply from that of the vitalist who limits his doctrine of the supernatural to the phenomena of life. The Christian man of science recognizes that natural law as it applies both to the animate and inanimate has a supernatural basis in its origin and in its perpetuation. Our sovereign and omnipotent God is both the creator and the sustainer of the universe for His own purposes. Herein we see both His transcendance to, and immanence in, the realm of nature.

Within such a perspective, the question whether biological life and its development do or do not supersede physico-chemical laws is of secondary importance. The possibility that many phenomena of life will yield to scientific analysis is beyond doubt. That life at some simple level will be produced in the laboratory, or that the mysteries of directed development will be solved, are still open questions. But, these are questions that the Christian biologist views with anticipation, not apprehension. In fact, as science challenges the mysteries of biological life and its development, the Christian biologist can participate with genuine enthusiasm, intently awaiting any major break-throughs that may lie ahead. For he realizes that each new discovery will be but a further revelation that our sovereign God has graciously given us of Himself.