I think there's a couple things people don't understand about reason, reasoning and logic. We classically separate them into deductive and inductive modes of reasoning; wherein, the former we have 100% certainty about the conclusions, given the premises; while the latter position has some degree of certainty less. But deductive systems (e.g., mathematics) are, as you say, based on presuppositions. As I would put it, deductive reasoning is system dependent. What works under one system may fail in another, and vice versa. Now the important thing to remember is that these deductive models we develop are such that they try to capture the real-world relations (or possible some-world relations) we try to describe, so that inasmuch as the real-world elements ideally match the variables in the system, we can use the system to describe what is going to happen. But as should be obvious, once we have an approximation like that we're slipping into the realm of inductive reasoning. What I find most important about inductive reasoning is that it is information dependent. It is also, in some sense, system depending inasmuch as it requires some form of methodology that we can appeal to that makes sense (pragmatically). Therefore, inductive reasoning utilizes first-order information as a basis for setting up some model to analyze it to make inferences; e.g., using information to approximate how much it fits some deductive model suspected to explain the relation. Consequently, such an approximation provides some degree of confidence in inferring a further conclusion based on those logical relations. Or, it may be based on an entire different kind of methodology that has proven to be accurate at explaining the world (e.g., statistics). What one should also recognize in this, however, is that the deductive models will not contain any information. Consequently, they cannot give us any information either. This leads me to believe deductive reasoning is not a mode of proof. I follow the notion that a proof needs to infer something "greater" than the premises. Deductive relations simply recast the given information so that you can "see it differently." But unless new information came into the analysis, then nothing was fundamentally changed. Inductive reasoning, on the other hand, leads us to infer something beyond the information. It takes as its premises a set of information, or knowledge K, to which we lead to an improved set of knowledge K' which includes our inference. Of course, that depends on one's epistemology and metaphysics whether or not they would consider such an inductive inference to constitute a proof or knowledge. Rationalists (e.g., Plato) believe just the polar opposite of the empiricist (me, to some degree). They would say it is in the deductive forms that we see knowledge, because it is 100% certain, unchanging, etc. In other words, they do not allow knowledge to be fallible or tenable. Knowledge has to be concrete and continuous (or static, if you will). The reason they discount induction is that a "black swan" may occur which makes the inference just wrong. Then our set K' for which the inference is included is wrong. But I do not see the problem in that. The discovery of the black swan is simply another piece of information that is included in the set so we have some new knowledge set K'' for which the inference disappears (or is altered in light of new information), and the black swan is included. In either case, we're still advancing our knowledge set. Deduction, to me, simply increases our tool set for analyzing possible relationships. I see no where that it has to apply to reality. The relationship direction seems to go from the world to the model, not the other way around, unless we say our logic shapes the world! This is why some people praise evidence. It is evidence that one obtains information to make inferences. However, one must also have a method for analyzing what constitutes evidence and a system for which we can utilize it. Otherwise, one is just arbitrarily praising evidence with no real understanding of it (for example, H_loves_C). I will end my diatribe now.

The problem you talk about in the larger paragraph toward the end seems to come from Alvin Plantinga’s evolutionary argument against naturalism (EAAN). Although your book is written by Keller, this argument didn't originate with him. I think Mr. Keller is borrowing from Plantinga's philosophy.

Plantinga's argument is foolish, as far as I am concerned, and it only convinces people who were already convinced before he started arguing.

I'll summarize Plantinga's argument for you, and you can tell me whether it's the one or similar to the one Keller uses.

To summarize it, Plantinga thinks the following:

..1.The truth of evolution is an epistemic defeater for naturalism.

..2.It is extremely hard to see, from the perspective of materialism, how it could be that the content of a belief plays a role in the causation of the behavior. Insofar as a belief enters the causal chain leading to behavior, it is by virtue of its neurophysiological properties, not its content.

..3.If evolution and naturalism are both true, human cognitive faculties evolved to produce beliefs that have survival value, not necessarily to produce beliefs that are true. Since human cognitive faculties are tuned to survival rather than truth in the naturalism-cum-evolution model,

..4.there is reason to doubt the veracity of the products of those same faculties, including naturalism and evolution themselves.

..5.However, if God created man "in his image,” then human faculties would probably be reliable.

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First, regarding 3, the survival value of beliefs has NOT been shown to be necessarily exclusive of truth value. He treats the two options as mutually exclusive, but this is not justified. It only makes sense that the ability of humans to draw true conclusions about predators would have greater survival value than drawing false conclusions about predators.

Second, point 2 is problematic.
2A) He merely assumes, from the beginning, a dualistic world view is true, i.e. that there is a difference between the neurophysiological properties of a belief and the content of that belief. Given Evolution and Naturalism, as he must assume in 3, the neurophysiological properties of a belief DO causally affect behavior.

2B) Plantinga is arguing that because it is “hard” for him to see something, that something is impossible. He is criticizing naturalism for not explaining how the content of belief affects behavior, but (2B1) he ignored naturalist literature on the subject (e.g. Chapters 3-6 of Ruth G. Millikan’s White Queen Psychology - Cambridge, MA: MIT Press, 1993), and (2B2) he merely assumed that what he considered a gap would never be closed or closable:

“Thus, after the dust has settled, Plantinga's underlying strategy proves to be very old: point to a stubborn, strategic explanatory gap, argue that (probably) they'll never be able to close it, then suggest a theistic explanation that does a better job (say by closing it without landing in self-referential incoherence, among other things). Not that Plantinga is invoking a God-of-the-gaps. Rather, he is advancing an anti-naturalism-of-the-gaps. Like all such explanatory-gap arguments, this one is vulnerable to, among other things, a kind of meta-inductive argument: in the past when the science on which naturalism draws was criticized for failing to explain this or that, the gap was eventually closed (or shown to be bogus); what was regarded as an impossibility, or at least an improbability, proved instead to be a lack of imagination or knowledge. Why not here, especially since naturalism continues to be a robustly progressing research program?” (John F. Post, Vanderbilt, review of Beilby, James, ed., Naturalism Defeated? – 2002. http://ndpr.nd.edu/review.cfm?id=1105)

Plantinga’s belief in 5 is perhaps worst of all. The idea that Yahweh created man “in his image” is a product of a Jewish mythology, which is riddled with historical and scientific problems. There is no good reason to believe Genesis’ account of the creation of the world or mankind, and there are tons of reasons to reject it. It is not history. My page on Genesis - http://www.geocities.com/investigatingchristianity/OTChrono.html .

Plantinga also uses suspect probability arguments in his anti-naturalist arguments [Fitelson and Sober’s “Plantinga’s Probability Arguments Against Evolutionary Naturalism” (1997)(fitelson.org/plant.pdf)].

>>You wrote, ". . . until I've accepted certain presuppositions illogically! For instance, I must accept that I and the universe exist, that there is an objective true and false, that the reason is a reliable tool for uncovering truth, that the constants I observe in this universe (gravity, behavior of elements, energy, etc.) will remain the constant into the future, and on and on."

1. What is "illogical" about accepting "that I and the universe exist"? As long as the definitions are decent, this should be the easiest thing for an individual to demonstrate to himself in a practical manner. Someone can say that he may be a brain in a vat, dreaming about himself and the universe, but his inductions regarding himself and the universe will still be valid within his mind and experience, and will still be the only reality he can know at the time, and there's no reason for him to worry over some imaginary "possible" vat unless some experiences begin to call for such a conclusion. There's nothing wrong with considering something to be provisionally demonstrated, and admitting that later information may bring new conclusions.

2. "there is an objective true and false" - this is not a presupposition that is necessary in order to seek knowledge. I don't necessarily need the word "objective;" I can simply work to continually increase my knowledge and compare it with the knowledge of those around me. When we disagree, if the disagreement is based on evidence, then I can assimilate the new evidence, and we can all work with the evidence, seeking further solutions. I can believe in "true" and "false" based on experiences of people's claims that 1) have withstood rebuttal and stand on as-of-yet-convincing evidence or reasoning - "true" (at least for now), and 2) have not withstood rebuttal or are not based on as-of-now-convincing evidence or reasoning - "false."

It is a matter of human experience that what one person has claimed to be "true" has often later been shown to be "false." Given the frequency of such occurrences, I see no problem in maintaining the very useful "true/false" distinction while admitting the often provisional nature of "truth" and being willing to address new evidence when/if it appears.

There's definitely something to be said for "This is the best we can discern at this time."

That being said, if someone does wish to assume the existence of "objective" truth and falsehood, that may be harmless enough (depending on how they define it), as long as what's considered "objectively true" is based on good evidence and as-of-yet-convincing reasoning, and as long as no one dismisses any future evidence that arises.

Also, if by "objective" one merely means that it can be measured at any time and demonstrated to anyone, then this is no longer an simple assumption, but is based on experience. That's still not to say that things can't change or that subsequent experience won't be subtler still, etc.

3. "that the constants I observe in this universe (gravity, behavior of elements, energy, etc.) will remain the constant into the future," - This also need not be assumed. If your current evidence suggests that they have been staying constant, then you can believe that they do, while still allowing that it might change in the future.

Things may change. More information may be acquired, leading to "updated" or revised conclusions. That's how knowledge acquisition works.

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@darkwolfofvoid

Thank you for your comment.

I see nothing I disagree with. I'm not sure either Induction of Deduction are forms of proof. After all, what can be proven?

@WindOnReed2

Thank you for your comment.

Keller is borrowing the argument from Plantigna. As far as I know you summarized his argument correctly. I still don't think the argument is foolish though. Here's why:

In your critique of point 3 you say, It only makes sense that the ability of humans to draw true conclusions about predators would have greater survival value than drawing false conclusions about predators. That makes sense if you already believe that human reason is reliable. However if human reason's main goal is not the pursuit of truth, but rather survival, you would never know if your reasoning abilities were flawed. From your perspective the pursuit of truth promotes survival, but what if Evolution made you to think that way? What if in reality the pursuit of truth did not enhance survival, only you did not know this because your reasoning abilities were corrupted? I don't think I'm explaining this clearly, but I hope you can understand. Basically, there's no way to object to the argument, because the argument questions reason itself. You can't use reason to overthrow an argument that doesn't respect reason.

As to your critique of point 2, it seems just. However, I don't understand how it relates to the argument I was writing about in the original post.

Finally, regarding your critique of point 5, I haven't gotten close to rationally determining that YHWH is the solution to this particular problem. However, I would like to address a particular statement that you made.

You write: There is no good reason to believe Genesis’ account of the creation of the world or mankind. Really, not a single good reason? So essentially everyone who believes the Genesis account, literally or figuratively, is either completely delusional, intentionally ignoring the facts or just stupid. Let me suggest something to you: adopt an attitude of intellectual humility. The problems with your statement are: (1) It offends your audience and automatically shuts them down. If you want your audience to change their position, don't tell them they're completely irrational. (2) The statement is false. I think I could find at least one good reason to believe in Zeus. If there were no good reasons to believe something, no one would believe it. (3) Your statement is arrogant. I once took a three year class in philosophy, theology and everything else. At the beginning of the class I thought I had life pretty much figured out. At the end, I was a much better thinker, but I realized also that I knew almost nothing. Truth is not something easy to find and there are good reasons to believe in any of the modern (and perhaps ancient) religions and philosophies. Rational debates and pursuits would get a lot farther if the participants were intellectually humble and realized simply, "I might be wrong."

Sorry for the tirade, but I hate those type of statements.

I'll reply to your second comment later.

@WindOnReed2

Regarding your other points:

(1) Perhaps it is not "illogical" to accept that the universe exists. It is however, "alogical". There is no way to prove the universe exists, no way to prove that sense perception is accurate. This universe I perceive does not exist within my mind, but outside it. The image of the universe I have within my mind may or may not exist. There is no argument I can make in favor of either position because the universe itself is necessary for argument.

(2) Perhaps we have different definitions of "objective". By objective I mean truths which exist apart from perception. (I believe perception discovers truth, not that perception is truth or that perception creates truth. Any are presuppositions too I realize but if the latter two are true then I don't see how we have any basis for actions that limit other people in any way.) If you don't accept that objective truths of this sort exist, what are you pursuing when you reason?

(3) To make conclusions about the future one must accept, for instance, that the law of gravity will still be in effect at that time. There's no way to prove that will be the case. Past results do not necessitate future ones.

What's the sad face?

Dude... don't drive yourself crazy, man. Stay grounded.

(NOTE: I say this as an educated man who has studied physics, mathematics, and music in university.)

And as a side note: I used to live near Death Valley. I now live in Thailand. I can tell you that both the rainbow of hues in the desert and the greens of the jungle are each equally beautiful, and each induce in me a sense of wonder. Just some food for thought.

Let's not forget the counterintuitive nature behind laws in general.  If it were truely a matter of "survival of the fittest" then would not laws be a means by which the weak and feeble might overtake the more "fit"?  Beyond that, and more to the point is that laws and the concept of "right and wrong" would be based on nothing concrete and the true Darwinist must concede that by his own creed Hitler would have been right and so would slavery as it was the dominant (or should we say 'most fit') train of thought at the time (interestingly enough Hitler borrowed much from the American Eugenics program which was born out of pure Darwinism)  Just some thoughts.

Metacognitive doubt (doubt about our very ability to reason, pick out truth from falsehood, etc.) plagues everyone, even the theist. How do we know God is good? Couldn't he be evil, and be tricking us into thinking he's good? Do we have reason to think he'd make us with reliable cognitive faculties? Couldn't that reason just be part of the lie?

It seems we are in the Cartesian circle along with the naturalist. So the mere possibility of metacognitive error shouldn't be enough to worry the naturalist, on my view.

I think that windonreed2 was heading toward a burden of proof argument: we should have faith that our cognitive faculties are more or less reliable until we have specific reason to think otherwise. I don't think we can do better than that.

With that said, Plantinga's argument would have a burden to show that evolution is likely to produce skewed cognitive abilities. Plantinga, I think, was aware of this, and that's why he did his fancy Bayesian analysis of the probability of our cognitive faculties being reliable given naturalism and evolution. It would be interesting to see if this analysis is really just a god-of-the-gaps style argument, I doesn't seem like one to me. So it would be to oversimplify Plantinga's argument to simply say it's a god-of-the-gaps argument, unless one really does delve into those Bayesian details.

BTW, interesting post.

You need to post an update on your intellectual journey!

In Christ, and for the gospel of the kingdom,
Brett