Nash begins the chapter by introducing Plantinga's concept of "noetic structure." Everybody has a noetic structure, which means simply "the sum total of everything [a] person believes" [p. 21] whether or not those beliefs are consistent with or even related to each other. As we shall see, one's noetic structure does not equal one's worldview, rather a worldview is a subset of your noetic structure, "a conceptual scheme by which we consciously or unconsciously place or fit everything we believe and by which we interpret or judge reality."
But before continuing, let me backtrack and comment on an example Nash gives of one of his beliefs which is part of the foundation of his own noetic structure. Nash writes, "One of my basic, unproven, perhaps unprovable beliefs is that other people have minds." And he footnotes this with the comment, "No one has constructed a good argument that others have minds."
This hints at what I've come to see as one of the major occupational hazards of doing philosophy (as opposed to, say, doing science): you expect important observations to be knowable by "pure reason". Again and again philosophers trip over that particular expectation. We learned as infants that other people have minds of their own, that their desires and intentions do not always accord with our own, and that things go better for us when we take other people's minds (particularly our parent's) into account. It is something that we all learned inductively through experience and the school of hard knocks, something which no one doubts unless they are attempting to do philosophy.
The existence of other minds is an empirical observation, an inductive hypothesis which we reached as infants by essentially approaching the world the way a scientist would. It is evidence that the scientific method (albeit unconsciously) is natural to humans. But let us become a philosopher and inductive reasoning from empirical observation is suddenly no longer good enough: we want proof. And this means, not evidence but a deductive argument from a set of premises. And here, Nash is telling us, "no one has a good argument that others have minds." Nor is he alone. Virtually every professional philosopher would agree.
And yet it's nonsense. True, no deductive argument can prove the existence of other minds. But that is because of a misunderstanding about deductive arugments. Consider:
All men have minds.
Socrates is a man.
Therefore Socrates has a mind.
That is a valid deductive argument, one which proves Socrates has a mind if its premises are correct. But premises always do one of two things: either they assert a definition ("let us say that Socrates is the name of a man") or they assert an observational fact ("there exists a man named Socrates"). Likewise, "All men have minds" can be taken as defining men as creatures who--by definition--have minds, or taken instead as making an observation of fact.
But how do we determine--ever--if an observation of fact is true? There is only one way: by inductive reasoning from observation and experience. Observational facts are determined inductively. What might be termed definitional facts are either declared ex cathedra or deduced by deductive argument from other definitional facts.
This is why philosophers spin their wheels trying to "prove" the existence of other minds. They are trying to reach a deductive conclusion drawn from definitional facts. Yet it is logically impossible to verify an observational fact that way. How then do we know that other minds exist? The same way infants do: by inductive reasoning from experience. The same method scientists use.
Furthermore, the conclusion of any valid deductive argument ("Therefore Socrates has a mind") will never be an observational fact. It will always be a deduced fact. No deductive argument will ever prove that others have minds; at the same time neither will any deductive argument ever prove that the sun is fueled by thermonuclear explosions, or that grass is green, or any other empirical observation.
I'm sure we will come back to this point later when we look at some of the attempts to prove God's existence by deductive argument. I suspect they will remind us of the misplaced attempt to prove the existence of other minds by deductive argument. A futile spinning of the wheels.
Let us move on, then, to worldviews. One of the plusses of Nash's book is that he sees the debate between theists and atheists as part of a larger debate between competing worldviews. He will devote a future chapter to how to choose between worldviews, but for now the important point he makes is that not all worldviews are created equal.
The right eyeglasses can put the world into clearer focus. The correct world-view can function in much the same way. When someone looks at the world through the wrong world-view, the world won't make much sense to him, or what he thinks makes sense will, in fact, be wrong in important respects. [p. 25]Furthermore, many of the intellectual clashes we see in society are actually clashes between competing worldviews, which is why they sometimes seem so intractable. "This is certainly the case," Nash writes, "between advocates of the prolife and prochoice positions on abortion. It is also true with regard to the growing number of conflicts between secular humanists and religious believers." [p. 25]
Disputants with conflicting worldviews often seem to be talking past each other, rather than talking to each other. Nash observes,
Most of us know people who seem incapable of seeing certain points that are obvious to us; perhaps those people view us as equally obdurate. They often seem to have some built-in grid that filters out information and arguments and that leads them to place some peculiar twist on what seems obvious to us. While this may sometimes be the result of something idiosyncratic to them, it is often a function of their world-view. [p. 25]In Faith & Reason, Nash is primarily concerned with the debate between two worldviews: Christianity and Naturalism. These seem appropriate choices, at least to someone with a Western European heritage. It is important to bear in mind, however, than Christianity and Naturalism are not monolithic. In reality there are thousands of Christian worldviews--mostly overlapping but sometimes with vital distinctions. Likewise there are differing version of Naturalism. Nor must we forget that other worldviews are out there, the most important from my perspective being Deism (which itself has multiple flavors) which I consider to provide the strongest challenge to my own worldview.
Nash makes what I think is a crucial point: "Every worldview has questions it appears to answer unsatisfactorily." [p. 26] This is true not just of Christianity but of every worldview. Most of us are are very aware of the weak points of Christianity because they have been examined and debated by theologians--by Christians themselves--for centuries. It is difficult to find a Christian who is not aware of the problem of evil, for example. Naturalism, on the other hand, has not been so carefully examined--certainly not outside of philosophical circles. Its weaknesses, the "questions it appears to answer unsatisfactorily" are there--but not well-known.
Nash's primary role in this book, however, is not to criticize Naturalism so much as advocate for the Christian worldview.
The case for or against Christian theism should be made and evaluated in terms of total systems. The reason why many people reject Christianity is not due to their problems with one or two isolated issues; it results rather for the simple reason that their anti-Christian conceptual scheme leads them to reject information and arguments that for believers provide support for the Christian world-view. Every world-view has questions it appears to answer unsatisfactorily. The task of negative apologetics is to show that none of the challenges to Christian faith is fatal; none of the problems Christian theism appears to have provides really sufficient reasons why people should reject it. The role of positive apologetics is first to offer support for essential Christian beliefs. But because any proper assessment of the Christian faith requires that it be seen and appraised as a whole, the more important job of positive apologetics is to explain the details of the Christian system and offer reasons why that world-view is superior rationally , morally, and existentially to any alternative system. [p. 26]To make that judgment, of course, requires us to apply negative & positive apologetics to that alternative worldview as well. If we don't know the ins and outs of both worldviews we are judging, we can't intelligently judge between them.
Nash goes on to discuss presuppositions or foundational beliefs, which he compares to axioms in geometry.
Once a person commits himself to a certain set of presuppositions, his direction and destination are determined. An acceptance of the presuppositions of the Christian world-view will lead a person to conclusions quite different from those that would follow a commitment, say, to the presuppositions of Naturalism. One's axioms determine one's theorems. [p. 28]Nevertheless, Nash is well aware that "nontheoretical factors" also greatly influence one's worldview. Some people have difficulty thinking clearly about concepts and beliefs; others have ingrained prejudices that prevent them from looking at things fairly. Other nontheoretical factors may stem directly from "the human heart, the center or religious root of our being." [p. 28] In all such cases, Nash avers, "[p]eople should be encouraged to dig below the surface and uncover the basic philosophical and religious presuppositions that often appear to control their thinking." [p. 29] I couldn't agree more. Often, we are not even aware of our presuppositions, and what we are unaware of we are unable to examine or compare with alternatives. We won't even know there are alternatives.
Next Nash outlines the "major elements of a world-view", which he lists as theology/atheology (is there a God?), metaphysics (the nature of ultimate reality), epistemology (the nature of knowledge), ethics (right & wrong) and anthropology (by which Nash means "beliefs about the nature of human beings"). There may be other elements which are not quite as prominent, Nash admits, such as viewpoints on how things ought to be, or why there is a discrepancy between how things are and how they ought to be.
Before completing the chapter, Nash takes pains to make it clear that not all Christians have an identical worldview--a matter obvious from the proliferation of Christian denominations around the world. Quite a lot of diversity can fit under the umbrella of the Christian worldview. "However," Nash advises,
it is also important to recognize that disagreement on some issues should result in the disputants's being regarded as someone who has left that family of beliefs, however much he or she desires to continue to use the label. For example, many religious liberals in the West continue to use the Christian label for views that are clearly inconsistent with the beliefs of historic Christianity. Whether they deny the trinity or the personality of God or the doctrine of creation or the fact of human depravity or the doctrine of salvation by grace, they make clear that the religious system they espouse is totally different from what has traditionally been meant by Christianity. A religion without the incarnate, crucified, and risen Son of God may be a plausible faith, but it certainly is not the Christian religion. [p. 33]The weakness of Nash's argument here lies in the word historic. Without doubt, traditional Christianity is exactly as Nash describes it here; but it is whether or not the traditional viewpoint is indeed historically correct which we must question. As someone who grew up in one of those "liberal" denominations to which Nash would deny the Christian label, I can attest that they would have replied that their Christianity was much closer to the actual teachings of Jesus, that it was in short "true" Christianity.
It was not, however, traditional Christianity, and if Nash had refrained from using the word "historic" I would not complain. As it is, if we decide the Christian worldview is on the right track it will then be necessary to tackle the matter of which. We'll revisit this question, I expect, in some future chapter.
Before closing, I'd like to briefly address a matter which Nash does not. That is the question why we care at all, or why we bother to debate about the relative merits of one or another worldview. What is the goal in engaging such a debate?
In the contest between Christianity and Naturalism, I submit, the goal is not to knock one or the other out of orbit, but simply to find out for oneself what is true. But why should we care whether our worldview is correct or not? Why does it matter whether our beliefs are true, so long as they are our beliefs? I admit it's difficult for me to understand why someone wouldn't care. Why am I alive? What's it all about? Why does anything exist at all? What is the best way to live? Is there life after death? What makes living worthwhile? What indeed is life? None of these are questions that can be answered by deductive argument, none of them are simple, and none can be resolved with any kind of finality. So why bother?
Many people don't bother. Or they grab a quick and easy worldview that makes them feel comfortable, allows them to push such questions under the table, or to pretend they've been answered. Some of us aren't content with that. We want to really know. We want the truth whatever it is.
Even if that truth is not ultimately obtainable. If we can't have finality we want, at least, the best answers we can imagine.