Alvin Plantinga on the concord between science and Christianity

As I continue speedily reading books this summer as preparation for a Fall class that will, in part, cover “nature of science” and “science and faith” questions, I recently finished Plantinga’s “Where the Conflict Really Lies”. (Spoiler - “where the conflict really lies” is not between science and Christianity, but between science and naturalism.) I left a short summary of the book here. If you’ve spent a lot of time thinking about these matters, you might not find much that is “new” in this book, but you will find the stuff you “already knew” stated carefully by a philosopher.

My favorite chapter was on the concord between science and Christianity and, whether you’ve heard it before or not, I thought it might be helpful to some to quickly trace his arguments. Now, worth saying up front that this is my summary, affected by my history and particular interests - your impression if you read the book might be slightly different, but I think this is a fair summary. One theme you will notice over and over again goes something like “science, in order to function, requires that the universe/humans have property X. If the Christian god exists, it is reasonable to expect the universe/humans to have property X. If he does not, if humans are just the result of natural selection operating on random mutations, then the existence of X would just be a fortunate accident / coincidence.”

So here we go.

Opening Thoughts

1. First of all, just as an historical fact, let’s notice that science largely arose in the Christian West. Of course you can always cry “coincidence!”, but given the supposed antagonism between science and Christianity, this seems a fact worth noticing.

2. It’s surprisingly hard to articulate what “science” actually is. Usually it is seen as an attempt to learn real truths about the world. But sometimes it as seen as an effort to produce models that yield testable predictions, with whether or not those models are “true” seen as a secondary question. [And I do appreciate that, as scientists study realms further and further from normal human experience - especially the quantum realm - it becomes harder for them to know whether their models are “true”, or the math just works out. Of course the “math worked out” for geocentrism for a long time too.] Plantinga leans more on the former definition, which is going to be what your average member of the public walking around thinks science is doing.

3. Critically, science also has an empirical component that distinguishes it from, for example, philosophy.

Point One: Science requires that we believe we can gain knowledge about the world, and actually can.

1. Christians believe human beings were created in the image of God. Exactly what this means has been a discussion topic as long as there has been a Church, but we may certainly say that God is a knower, the supreme knower. Humans, created in his image, therefore also have an ability to know things about our world.

2. But how, exactly, do we have that ability? We have that ability because God created both us, and the world, such that there is a fit between the world and our cognitive faculties that allows us to gain knowledge about the world. Medieval theologians talked about the “adequation of the intellect to reality”.

3. Science might seem “modern’, but it is at heart an extension of our ordinary ways of learning about the world. [It is sometimes called “formalized common-sense” or some such.] Therefore for science to work, there must be a fit between the world and our cognitive faculties. Christians believe God created us, and the world, with that fit.

4. Meanwhile we shouldn’t expect that natural selection operating on random mutations, the main competitor framework in the US today, is at all interested in humans having true beliefs about the world. It only cares if we can have offspring, by whatever means.

Point Two: Science requires an ordered universe.

1. For science to be successful, the world must display much regularity and predictability. It is easy… well maybe not terribly easy, but you can imagine theoretical universes that were simply chaotic.

2. Christianity teaches that God governs the world - what happens does not finally happen by chance, but by virtue of his providential governance. To do science requires that we believe the world is ordered. This belief is sensible given our belief in the rationality of God.

3. God creates moral laws, but he also created the laws of nature, and a world that obeys those laws. Samuel Clarke wrote that “What men commonly call ‘the course of nature’… is nothing else but the will of God producing certain effects in a continued, regular, constant, and uniform manner.”

Point Three [sort of a unity of #1 and #2]: Specifically, the order of nature can be thought of in terms of laws, and we are able to grasp these laws.

1. The regularity of nature is often thought of in terms of laws.

2. Moral laws are promulgated for free beings, who may choose to obey or disobey them. The laws of nature are promulgated for inanimate matter, who must obey them.

3. To exist as a human endeavor, science not only requires lawful behavior on the part of the world, it requires that these laws be discoverable by us. The laws must not be too complex, or deep, or beyond our human abilities. And, “lucky us”, it seems that they are not. Again, this fits well with Christianity and its doctrine of the image of God.

4. Kepler: “Those laws are within the grasp of the human mind. God wanted us to recognize them by creating us after his own image so that we could share in his thoughts…”

Point Four: But what is a “law” exactly? To be a natural “law” speaks of some necessity, but HOW are they necessary? Christianity helps us make a precise definition here.

1. To really be a law requires some element of necessity. The world is full of true, universal statements that we would not call “laws”. [I have an orange cat. This statement is true, true for all people at all times, but no one would call it a law of nature.]

2. But… how are the laws of nature necessary? What is this necessity? It isn’t a logical necessity. You can imagine theoretical other universes with different laws. Philosophers have struggled to answer this question.

3. Christianity is helpful here - we can think of natural laws as both a consequence and measure of divine power. God is omnipotent. We are not. The laws of nature are decrees, from God, that no creature may act against. If it is a natural law that no object can travel faster than the speed of light, for example, then we will never be able to get a space probe to the nearest star system is under four years, period, end of discussion. [On the other hand I could have picked up the black cat from Petco on that fateful day instead of the orange cat.]

Point Five: Mathematics is bizarrely effective in describing the world. And humans can do math.

1. Our world is mathematically describable in ways that shows great complexity, yet also deep simplicity. This is astounding. [Yes, all scientists from time to time are struck by how bizarre and astounding this is.]

2. The effectiveness of mathematics in science as part of our ability to, after hard work, know things about the world, seems perfectly appropriate if a God created both us and this world.

3. Let us also notice that, from the perspective of naturalism, it is unreasonable for us to be able to understand and practice the sort of mathematics needed in science. The mathematical depth required goes magnificently far beyond that needed for survival and reproduction. Ancient man roaming the African plains presumably would not have benefitted in the slightest from an ability to solve differential equations, yet we have that ability.

Point Six: Science requires that we be able to reason inductively and so reach true beliefs about the world.

1. We take it for granted that the future will resemble the past. I have eaten bread hundreds of times in my life - I trust that the next slice of bread will also not kill me. [I’m getting repetitive here but, again, you can imagine a theoretical universe in which this is not true!]

2. We also reason inductively, and “inductively generalize” in our scientific theories. We examine the Law of Gravity in many circumstances and then trust that it holds in all - of course, we cannot and never will examine every circumstance. By our nature, we believe that, as Thomas Reid put it, “what is to be, will probably be like to what has been in similar circumstances”. Science could not really exist, not to any great extent anyway, without this conviction.

3. But why in the world should we assume that what we know for certain objects, right now, is also applicable to other objects, in the future? Well, again, that assumption is reasonable given theism. The ability to successfully reason inductively is just another aspect of our intellect being fitted to reality.

Point Seven: Science requires us to pick between theories on the basis of something other than just the evidence / predictive power.

1. Scientific theories are underdetermined by the evidence - there are essentially an infinite number of theories that would fit any set of data.

2. Or, put mathematically, there are an infinite number of curves that could be fitted to any finite set of data points.

3. Nonetheless, scientists must pick ONE to prefer, and they pick that one on the basis of other factors, like simplicity and beauty.

4. This is because we naturally value simplicity and beauty. Again, it is reasonable to think that if we have a God that values simplicity and beauty, those parameters will be reflected in his creation, and in our concern for those same things. From a naturalistic perspective, this could be nothing but a cosmic coincidence.

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