Chapter 1: Evolution and Christian Belief (Part 1)

I. Motivating the Project: Why should anyone care about conflicts, whether real or imagined, between science and faith?

Plantinga’s book, as the title implies, is all about alleged conflicts between the scientific and theistic worldviews. Before he begins to address any of those allegations in particular, however, he wants to show that his project is an important one. He does this, in short, by upholding the commonsense view that the claims of modern science, as one of mankind’s greatest intellectual achievements, deserve to be taken seriously and not simply disregarded whenever they appear to conflict with our accepted religious tradition. Since it this claim that really motivates Plantinga’s entire project here, I think would be worthwhile to spend some time entertaining potential objections. First, the quote:

It would be a serious matter if any of these alleged conflicts [between science and theism] were genuine. First, science is widely and justly celebrated as a splendid intellectual achievement – perhaps mankind’s most splendid effort along these lines; but then any human enterprise in serious conflict with it has some explaining to do. Second, science does or should enjoy particularly high regard among Christians [because modern science is an impressive way in which humankind communally reflects the divine nature and is a striking development of the image of God in humanity].[1]

Q1: Do you agree that religion should be accountable to science, or vice-versa? If so, why, and to what degree?

As Plantinga notes, allegations of conflict between science and religion have a long history, extending back at least to the 17^th century conflicts between the Catholic hierarchy and early astronomers like Galileo and Copernicus. Eventually, however, these initially unorthodox ideas managed to gain mainstream acceptance, and are now fundamental to our conception of the universe. So…

Q2: How should we strive to negotiate the disagreements (whether real or apparent) between our scientific and religious authorities? What standards should we use to evaluate their rival claims and determine which, if either, to adopt?

On pages 6-7, Plantinga challenges certain historians’ representations of the church’s early conflicts with science as being somewhat sensationalized. He is particularly critical of the interpretation that portrays the religious authorities as “the force of repression and tradition, the voice of the Old World, the dead hand of the past, etc.”

Q3: How do you think a disinterested observer who read of these events (e.g., the church’s persecution of early astronomers) for the first time in his/her history book would interpret them? How do you think he/she should interpret them? Do you think that we, as non-disinterested parties (whether theistic, agnostic, or atheist), should strive to have the same outlook as the disinterested observer, or does our perspective from within give us special insight that is also valuable in interpreting these events? How might you motivate your case to the disinterested observer?

Q4: Does the general tendency that we observe for orthodox religious views to gradually adapt, and ultimately conform, to the views of science say anything significant about the general reliability of these two enterprises? Does the history of religion provide something like a pattern from which we might extrapolate and conclude something stronger about its rightful place in influencing our present opinions on empirical matters (e.g., that the church merely “represents the force of repression and tradition, the voice of the Old World, the dead hand of the past, etc.”)? What further considerations might there be to justify the continued confidence of religious people in the church as an authority on matters about which they have historically so often fallen on the wrong side of?

The questions above could easily segue into two of my favorite areas of philosophical debate, both relating to the field of epistemic normativity. These are:

(1)  Disagreement: Does the fact that someone else disagrees with us give us a reason to adjust our beliefs, or at least our confidence in our beliefs? What if that someone else is recognized as being of equal or superior intellectual capacity to ourselves?

(2)  Formation of New Opinions: Where do our opinions come from, and what things can cause or influence one to change their opinions? Why do some things (experiences, arguments, feelings, intuitions, etc.) cause or influence some people to change their opinions, but not others? How strongly correlated are our beliefs to a thing’s likelihood of being true (i.e., are our beliefs reliable indicators of truth)? Are there other stronger indicators of a thing’s likelihood of being true? (We talked a little bit about this one in our last discussion)

Since both of these are somewhat tangential to the main subject of our discussion, however, I’ll leave it to you guys to decide whether or not you’d like to pursue them further…

II. Allegations of Conflict: In what ways are science and religion alleged to be incompatible with one another? Are these conflicts real or imagined?

Ok, now that we’ve given some critical thought to the assumption that motivates Plantinga’s project, let’s move on to considering the actual allegations of conflict that his book seeks to resolve. These are outlined on page 3 and can be condensed as follows:

Claim 1: Religion and science are incompatible because science affirms evolutionary theory, which is at odds with the Christian/theistic worldview.

Claim 2: Religion and science are incompatible because theism affirms that God acts specially in the world (i.e., through miracles and other kinds of direct action), which is at odds with the scientific worldview.

Claim 3: Religion and science are incompatible because the epistemic attitudes characteristic of them are incompatible.

Since only the first of these claims is addressed in chapters 1 and 2, that’s where’ll focus this week’s discussion.

In order to evaluate the claim that religion and science are incompatible because of their conflicting views about evolution, Plantinga first lays out what, in his opinion, evolutionary theory entails. The definition that he provides is presented below:

The “six theses of evolutionary theory” (construed broadly):

(1)  Ancient earth thesis – “the earth is very old, perhaps some 4.5 billion years old”

(2)  Progress thesis – “life has progressed from relatively simple to relatively complex forms”

(3)  Thesis of descent with modification – “the enormous diversity of the contemporary living world has come about by of offspring differing, ordinarily in small and subtle ways, from their parents”

(4)  Common ancestry thesis – “life originated at once place on earth, all subsequent life being related by descent to those original living creatures”

(5)  Darwinism – “there is a naturalistic mechanism driving this process of descent with modification, the most popular candidate [being] natural selection operating on random genetic mutation”

(6)  Naturalistic origins thesis – life itself developed from non-living matter without any special creative activity of God but just by virtue of process described by the ordinary laws of physics and chemistry.

Plantinga proposes the convention of using the term evolution to encompass the first four of the above theses, Darwinism to include through the fifth, and treating the sixth separately as its own independent thesis (p. 10).

Q5: Do you agree with the way Plantinga has characterized evolutionary theory? Is he right to treat theses 5 (Darwinism) and 6 (Naturalistic Origins thesis) as independent of – i.e., not logically entailed by – evolutionary theory proper? If he is, why do you think so many people treat theses 5 and 6 as proper elements of evolutionary theory?

Plantinga’s Critique of Dawkins’ Argument

The Darwinian claim (according to Dawkins):

(1)  There is a history that traces in detail the development of all forms of life in a stepwise fashion, as evolutionary theory describes

(2)  There is good evidence for current views as to the overall shape of the history

(3)  We have some informed guesses as to how, at a high level of abstraction, some of the transitions occurred

Dawkins sets up his argument by posing the following three questions. The answers to these will provide the justification for his conclusion, i.e., serve as premises in his argument for naturalism.

(1)  Is there a continuous series of Xs connecting the modern human eye to a state with no eye at all?[3]

(2)  Considering each member of the series of hypothetical Xs connecting the human eye to no eye at all, is it plausible that every one of them was made available by random mutation of its predecessor?

(3)  Considering each member of the series of Xs connecting the human eye to no eye at all, is it plausible that every one of them worked sufficiently well that it assisted the survival and reproduction of the animal concerned?[4]

Plantinga condenses these three questions into the following formula, which he calls the Big Question (BQ):

BQ: Is there a path through organic space connecting, say, some ancient population of unicellular life with the human eye, where each point on the path could plausibly have come from a preceding point by way of a heritable random genetic mutation that was adaptively useful, and that could plausibly then have spread through the appropriate population by way of unguided natural selection?[5]

Dawkins’ Answers (as presented by Plantinga):

To 1: “It seems to me clear that the answer has to be yes, provided only that we allow ourselves a sufficiently large series of Xs.”

To 2: “My feeling is that, provided the difference between neighboring intermediaries in our series leading to the eye is sufficiently small, the necessary mutations are almost bound to be forthcoming.”

To 3: “Yes,” (then provides a possible account of how the eye may have formed through such a process)

Plantinga’s Objections

Objection 1: “There is surely no guarantee that there is a not too improbable path through organic space from some early population of unicellular organisms to human beings, or for that matter, to fruit flies.”[6]

The premises, his answers to questions (2) and (3) above, are controversial, unsupported, and pretty much guesswork. There is no attempt at the sort of serious calculation that would surely be required for a genuine answer.[7]

Objection 2: “Even if [Dawkins] is right about the answers to (2) and (3) it doesn’t follow that the whole path is plausibly possible in this sense – that is, it doesn’t follow that the path is not astronomically improbable. That is because of the temporal constraint imposed. Suppose there have been multicellular organisms for, say, a billion years. This means that the series can’t be arbitrarily long and the distance between the points arbitrarily small.”[8]

[I]f it’s to be relevant, the length of the series will have to be constrained by the time available, and each step in the series will have to be such that it can arise by way of genetic mutation from a previous step. Furthermore, (and crucially,) each mutation will have to be fitness-conferring (r at least not unduly costly in terms of fitness), so that it’s not too improbable that they be preserved by natural selection.[9]

Q6: What is meant by “could plausibly” in the sentence “each point along the path is such that it could plausibly have come from a preceding point on the path by way of a heritable random genetic mutation”?

Plantinga says that Dawkins defines plausibility in terms of biological probability:

Biological possibility – Is to be explained in terms of probability: “A given point on a path could plausibly have come from a preceding point by way of genetic mutation just if it is not too improbable that do so.”[10]

Objection 3: “If he is successful, what Dawkins really shows is that the arguments against there being a Darwinian series are not conclusive. What he shows, if he’s successful, is that for all we know there is such a series, so that for all we know it’s possible that the living world came into be in this fashion.”[11]

Plantinga thinks that the above argument form (p is not astronomically improbable, therefore p) is so uncompelling as to suggest that it was meant to rely on further premises not explicitly stated, namely (1) that theism represents the only alternative to naturalism,[12] and (2) theism isn’t plausible (namely, because design doesn’t explain organized complexity, but rather presupposes it, since the designer would have to be as complex as what it creates/designs).[13] Plantinga summarizes the adjusted argument as follows:

Dawkins’ argument reformulated

(1)  There are just two explanations of life: unguided Darwinism and an explanation, guided Darwinism, perhaps, that involves design.

(2)  Guided Darwinism, involving design, is no explanation at all since it already presupposes complexity by positing an intelligent designer.

(3)  Therefore, unguided Darwinism is the only explanation.

I actually think that Plantinga is right here. God or no God, science needs a mechanical explanation for the stunning diversity we observe in this world – a plausible answer to the question of how we got from there (the state of affairs described by cosmologists and astrophysicists) to where we are today (“this stunningly intricate world with its enormous diversity and apparent design”). The mechanism of natural selection seems to have all the right tools for the job, and it’s not yet obvious that we’re in any need of anything further. Perhaps if the serious calculations Plantinga faulted Dawkins for not providing were furnished, then natural selection would seem an inadequate explanation. In his 2012 book Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly False, philosopher Thomas Nagel suggests that the critical arguments raised by proponents of intelligent design actually do raise enough legitimate questions to demand a more thoughtful response from evolutionary theorists. What do you think?

Q7: Do you think that natural selection is adequate to the task of explaining the “stunningly intricate world with its enormous diversity and apparent design”? Why or why not?

Q8: What do you think about Plantinga’s claim on page 24 that the theist has more freedom with respect to this debate to, essentially, follow the evidence where it leads, since God presumably provides an alternative explanation for what is observed? Does a religious worldview make it easier or more difficult to infer to the best explanation (both generally as well as with respect to this particular question)?

Plantinga’s Objections to Dawkins’ Reformulated Argument

Objection 4: “[Dawkins’] argument doesn’t depend on the facts of biology; it is substantially independent of the latter.”

Objection 5: “We aren’t trying to given an ultimate explanation of organized complexity, and we aren’t trying to explain organized complexity in general; we are only trying to explain one manifestation of it. And (unless you are trying to give an ultimate explanation of organized complexity) it is perfectly proper to explain one manifestation or organized complexity in terms of another.”[14]

Explanations come to an end; for theism, they come to an end in God. For any other view on the same level of generality they also come to an end. The materialist of physicalist, for example, doesn’t have an explanation for the existence of elementary particles or, more generally, contingent physical or material beings; that there are some is, from that perspective, a brute fact. It isn’t easy to say precisely what counts as begging the question; but to fault theism for failing to have an ultimate explanation of mind is as good a candidate as any.[15]

Here, Plantinga offers a final reconstruction of Dawkins’ argument:[16]

(1)  The existence of God is monumentally improbable – about as probably as the assembly of a flight-worthy Boeing 747 by a hurricane roaring through a junkyard.

(2)  It is not monumentally improbable that life should have developed by way of unguided Darwinism. In fact, the probability that the stunning complexity of life came to be in that fashion is greater than the probability that there is such a person as God.

(3)  We should prefer unguided Darwinism to an explanation involving Design.

(4)  There are just two explanations of life: unguided Darwinism and an explanation, guided Darwinism, perhaps, that involves design.

(5)  Therefore, by an inference to the best explanation, we should accept unguided Darwinism.

Objection 6:  “Conced[ing,] for the moment, that unguided Darwinism is more probable than an explanation involving design, does it follow that the former is to be preferred to the latter? There is more to a good explanation than the probability of the explanans."

Q9: What are the criteria for comparatively evaluating competing hypotheses/explanations? Applying these, is there any decisive reason to prefer the theistic explanation over the naturalist explanation, or vice-verse?

Objection 7: “If all the explanations are highly unlikely, am I obliged, nonetheless, to pick and endorse one of them?...What ever happened to agnosticism, withholding belief?”[17]

Objection 8: Why think the existence of such a person as God is unlikely in the first place?...According to the classical conception, God is a necessary being, i.e., He exists in all possible worlds. The objective probability of God’s existence, therefore, is 1.”[18]

Plantinga concludes: “Dawkins gives us no reason whatsoever to think that current biological science is in conflict with Christian belief.”[19]

Q10: Are you satisfied with Plantinga’s defense in this chapter? 

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[1] Ibid., 3-4.

[2] Pragmatism, 26-27.

[3] Note that, as Plantinga points out, “the human eye is just a stand in for life forms generally” (p. 19).

[4] Ibid. 18.

[5] Ibid., 19.

[6] Ibid., 22.

[7] Ibid., 23.

[8] Ibid., 23.

[9] Ibid., 21.

[10] Ibid., 20.

[11] Ibid., 25.

[12] “For the nontheist, undirected evolution is the only game in town, and natural selection seems to be the most plausible mechanism to drive that process. Here is this stunningly intricate world with its enormous diversity and apparent design; from the perspective of naturalism or nontheism, the only way it could have happened is by way of unguided Darwinian evolution; hence, it must have happened that way; hence there must be such a Darwinian series for each current life form” (ibid., 24).

[13] “Any God capable of intelligently designing something as complex as the DNA/protein machine must have been at least as complex and organized as that machine itself…To explain the origin of the DNA/protein machine by invoking a supernatural designer is to precisely explain nothing, for it leaves unexplained the origin of the Designer” (ibid., 26).

[14] Ibid., 27.

[15] Ibid., 28.

[16] Ibid., 28-29.

[17] Ibid., 29.

[18] Ibid., 29-31.

[19] Ibid., 31.