Christianity and Computer Science at Calvin College

Harry Plantinga

Calvin College Department of Computer Science

Computer Science

Computer science is a discipline with two aspects. On the one side it is an engineering discipline: it involves the planning, design, construction, and maintenance of computer systems. Its subject matter is a corpus of techniques for analyzing problems, constructing solutions that won’t collapse, guaranteeing and measuring the robustness of programs. (It is an immature engineering discipline, one realizes, when Microsoft Windows crashes yet again.)

On the other hand, I believe that it is also a science in the sense that mathematics is a science. It is the study of computation and computability, the study of algorithm. It does not frequently use the hypothesis-test method of studying nature, but it does involve the study of nature, in my opinion. The discovery of an aesthetically pleasing algorithmic solution to a difficult problem, the elucidation of the properties of the algorithm – these are ways of learning about God’s creation. The world is created in such a way that certain problems have efficient solutions and other problems have no algorithmic solution at all. In fact, there is a rich structure to algorithmic complexity. Computer science investigates this structure.

In this scientific approach to the discipline, as we learn about God’s creation, we also learn about God. We see something of the infinite riches of his wisdom and knowledge, his grace of hidden riches provided for humanity, his beauty. The appropriate attitude of the computer scientist is doxology. It is wonderful that any computable function can be embodied with a combination of two basic types of logic gates or that simple motions of rods and levers or rebounds of billiard balls can in principle play chess or factor a large number.

Our belief that creation is real and has a certain, fixed nature affects our approach to the discipline. We admit that there may be limits on computability and complexity of problems. We are willing to believe proofs regarding these matters. Yet because creation is fallen, we do not expect to find unadulterated perfection in computing. Even if a simple computer program were proven correct, we would allow for the possibility of hardware failure or a misunderstanding of the original problem. We take appropriate precautions and do not entrust too much to computers. We acknowledge that there will often be harmful as well as beneficial effects in the computerized solution of a problem.

Foundational Issues

There are also foundational issues in computer science in which a reformed, Christian perspective may affect research and teaching. One issue that interests me is the relationship between computing and thought. Our beliefs about the nature of humanity may affect our expectations about the future possibilities for artificial intelligence. On the other hand, the discoveries of artificial intelligence may help us improve our understanding of the nature of humanity.

In his Institutes, Calvin strongly affirms that though the soul has organic faculties, it is immortal and separable from the body.1 He argues that human ability to reason, perform scientific investigation, invent “marvelous devices,” even “divine the future – all while man sleeps” are “unfailing signs of divinity in man.”2 Yet in a day when computers prove theorems and play chess, it is appears that some of the kinds of rationality Calvin had in mind are in fact mechanizable. Since finding regularities in the world, devising ingenious solutions to problems, and proving theorems can be performed by purely mechanical means can be done by computer, it is necessary (and possible) to define more closely what may be “unfailing signs of divinity in man.”

Aquinas places the intellect in the higher powers of the soul and memory and reason as parts of the intellect.3 Today, one would have to make more distinctions. Memory and reason – in the sense that computers have memory and can reason – are now known to be physical processes.

A conclusion some draw is that rationality is not, after all, unique to humans. Even machines can be rational. They have already been shown to be able to perform many tasks requiring rationality; there is no reason to think that others will not succumb eventually. If there is anything unique about humanity, it is not reason.

However, other conclusions are possible. I am inclined to conclude that whatever is unique to humanity, an “unfailing sign of divinity,” is other than what computers do. Theorem proving, playing chess, and other forms of symbol manipulation according to rules are not uniquely human activities; after all, they can be performed by a machine. The rational soul is not unique in its computational and logical abilities, but in some other capabilities, such as those for intent, love, choice, and knowing God. If there is an aspect of memory and reason unique to the human intellect, it would have to be located in the meaning associated with the memory and reason.

In such discussions about the nature of personhood, presuppositions affect the range of conclusions that can be admitted. The materialist is limited in the possible ways of understanding humanity. Since she believes that all is material, she concludes that people are material objects, subject to physical laws. She is inclined to accept without proof the idea that any sort of “thinking” a person can do can be simulated by computer. And since the brain and the machine use different but functionally equivalent computational processes, the machine can think in the same sense as the brain.

Christians, who are not bound by the presupposition of materialism, are free to consider other possibilities, such as that God exists and is not a material object, that God is capable of working outside of physical law, and the traditional Christian view that people have an immortal, non-physical, separable soul, immediately created by God, endowed with the supernatural capabilities of love, will, and knowing God. Yet only the bravest or most foolhardy among us will claim to understand the nature of humanity and the union of humanity with the image of God. The Incarnation is after all one of the greatest acts of God and one of the greatest mysteries of the faith.

Foundational issues such as this one affect not only the theories we are willing to consider but the research programs we take on and even our hopes for eternal life. I recently received e-mail from the “Lazarus Foundation,” which is attempting to set up an organization to research the making of backups of “brain programs.” The idea is that in the event of major system failure (e.g. a plane crash or heart attack) the most recent brain program backup could be installed on alternate “wetware,” perhaps a cloned body, thereby achieving eternal life. But I haven’t yet met a Christian whose hope for eternal life is in having his brain program ported to another system. Even Christians who believe that people are material objects apparently don’t limit the soul to a “brain program,” a set of symbols appropriately manipulated. Our future is a new resurrection body and a new heavens and earth.

Computer Engineering

The perspectival issues that arise in the engineering part of the discipline include motivation for work and choice of work area, professional responsibility, and ethics. We are in the image of a creative God, and we also love to create. There is a joy in creating something beautiful and useful out of the raw material that God provides. Love for God and neighbor is expressed in creating systems that solve problems, meet needs, and build up the church. And a unique power of this tool is that programs can be copied at almost no cost. Serving millions of people is as easy as serving one.

Professional responsibility and ethics are not only found among Christian computer engineers. The ACM, the professional organization for computer scientists and engineers, publishes a code of professional responsibilities and ethics, to which ACM members voluntarily subscribe. However, the motivation for subscribing to ethical standards among Christians is different and perhaps stronger. The professional may find more reason to go out of her way to serve well when motivated by gratitude to God.

Social Issues

Finally, there are legion social issues that arise from the ubiquity of computing and computer-mediated communication. Computerization has transformed society in many ways. It has transformed our electronic and mechanical devices, our workplaces and types of work, our communication, and our recreation and leisure. We enjoy our sedentary communication and our recreation consisting in reading e-mail, browsing the web, and chatting on-line, but obesity is bursting out at the national seams. We enjoy the convenience of on-line purchasing, instant messaging, and electronic funds transfers, but our personal information, preferences, and finances are ever more closely tracked. We favor digital music, electronic books, and satellite TV, without accounting for the loss of the advantages of the physical artifact and the loss of consumer rights encrypted in electronic delivery. We e-mail and chat with our friends on-line, but we don’t often consider the earthy fellowship and shared lives lost in such ‘cyber society.’

Some are even suggesting that computers and electronic media are changing the way people think. Several sources of sound, images, and messages available at once combined with homework or computer games seem to be a common state for modern youth. Are we losing the ability to concentrate on a single subject, reason logically, and carry on a linear chain of reasoning? These are issues for cultural discernment from a Christian perspective.

As Christian computer scientists and engineers, we approach the study of our discipline in an attitude of doxology and service. We praise God as we study nature, and in gratitude we serve others. We are careful to honor God in what we do, and we find that in loving God we love others and in serving others we serve God. We choose the problems we will address through of a motivation of service, and we do our best to make our systems reliable, easy to use, and helpful, to honor God. We consider the social implications of our work and do our best to spur the beneficial aspects of computing. And in our service we find joy.

1. Institutes of the Christian Religion, tr. Ford Lewis Battles, 1960, I.v.5.

2. Ibid.

3. The Summa Theologia, by St. Thomas Aquinas, First Part, Q. 79.