As George Orwell explained in his 1949 book, titled "1984," the way words are defined can play tricks with our thoughts - and even reshape them to some extent. In particular, a single word with two similar, but significantly different, definitions can present considerable confusion - and cause us to muddle our logical distinctions. One such word is our English word "because" which plays a key role in our concept of how logic itself works. The word "because" has two different meanings which are sufficiently similar that we often forget that they are different at all.
The first meaning of the word "because" (hereafter "because ") is the "cause and effect" sense of the word. When I say, "I am healthy because  the food I eat is healthy," I mean that the healthy food which I eat is a cause which produces the effect that I am healthy.
The second meaning of "because" (hereafter "because ") is the "grounds to conclude" sense of the word. When I say, "I know the food I eat is healthy because  I am healthy," I mean that the fact that I am healthy after eating that food, provides the grounds for me to conclude that the food must have been good for me and not poisonous.
Notice that my good health does not cause the food I have eaten to be healthy; nor is the fact that I eat healthy food necessarily grounds for concluding that I am, or ever will become, healthy. The two ideas are quite different. In fact, as will be shown, there is one critical sense in which these two meanings are essentially opposites (like "give" and "take"); yet they are tangled together in our minds under the single word "because" (this time I mean the English word "because" - hereafter "because "). If the concepts "give" and "take" had been combined under the single word "transfer," moral ideas like "donating" and "stealing" might have required lengthy explanations to sort out. The following lengthy explanation is necessary because  because  has two easily confused meanings.
Let us assume that a man named Sam has told us that high-fiber food is good for us. Our task is to decide whether or not to believe him. If we are gullible we might decide to believe Sam simply because  he told us high fiber food was good. If Sam were a respected friend we might believe him even if we aren't particularly gullible because  he had earned our trust by his actions in the past. If Sam were also an expert in nutrition, he might earn more credibility in our minds because  of this.
Next, let us assume that a chain of events happens which erodes our trust in Sam: First we learn that his brother Joe sells high-fiber food. We realize that this might influence Sam. He might support high-fiber food because  his family loyalty tends to influence him. We should be less trusting in Sam's advice because  of this. Next we learn that Sam's brother pays him to tell us high-fiber food is good. Sam only says it because  he is getting paid to. Now we know that Sam is influenced and we should be even less trusting because  of this. Or maybe we learn that Sam is just a robot constructed by Joe. Sam tells us high fiber food is good because  that is how Joe built him. Now we cannot trust Sam at all because  Sam's advice is mechanically caused. Instead we would have to decide whether or not to trust Joe; or, better yet, we could do our own research and come to our own conclusions.
But now there is one last twist to this story: We go in for our weekly checkup at our neurologist who shows us an x-ray of our brains. There, to our chagrin, where we expected to see our brains, we behold the image of a small computer designed by Joe. At this point we cannot even trust our own thoughts. Why? Because  they are caused by a source which we have not logically evaluated; our thoughts are what they are simply because  that's how Joe programmed them. Can we ever trust Joe? There is no way we could ever decide; our own thoughts could not be trusted. We could not even perform our own research on high-fiber food; there would be no way we could properly trust our evaluation of the results.
In this story, the more causality (because ) encroached upon the process of our logic and reasoning, the less reason we had to trust the basis for that reasoning (because ). When causality finally became absolute, our grounds for believing our conclusions disappeared completely. This is the sense in which because  and because  are opposites. They are mutually exclusive in our thought processes. When a person has a mechanical reason to say something (e.g. because  they are prejudiced, or because  they are drunk, etc.) we believe we are justified in disregarding any "authority" their opinions might otherwise have carried.
Although this story about Sam and Joe was fictional, it still raises an important question about our own brains. How much do we know about how they were "designed"? Whether it was by evolution, intelligent design, or perhaps by some combination of both, the question is still somewhat disturbing; How much can we "know" about our own "knowledge"? If our brains are defective in some critical sense, will that defect protect itself from our ever discovering it?
This problem turns out to be very similar to the one raised by Chris Cole, regarding the is/ought dichotomy. As Chris pointed out, it appears to be extremely difficult to bridge the gap between what "is" and what "ought to be." The preceding argument explains why: What "is" (a mere chain of physically caused effects) actually displaces or drives out what "ought to be" (a basis or grounding for concepts like truth or perhaps even morality).
An easy way out of this might be to claim that concepts like truth and morality are mental illusions; but there is a very serious problem with this approach: the more the universe yields up its secrets to the advance of scientific inquiry, the more it appears that pure mathematics could very well turn out to be the underlying basis for all physical reality; rocks seem solid to us only because the quantum numbers which define their myriad states cannot assume overlapping values. Further, it is nearly universally held to be true that both mathematics and logic would still hold the same rules if there were no humans to discuss those rules or even if there were no universe whose "particles" obey the mathematically defined laws of physics.
Since our human logical and mathematical reasoning would seem to be a mere shadow of the logical and mathematical basis for all physical reality, it might seem a bit strange if we, the shadow, should choose to identify the substance as a mere illusion. This suggests that perhaps something major actually might have gone wrong with human thought - at least for those individuals who regard their own conclusions to be an illusion.
At this point we will have to make a completely arbitrary decision:
A) We can choose to trust our own thoughts.
B) We can choose not to.
If "B," then we can stop here. There can be no rational
approach to this (or any) problem. Hedonism suggests
itself as the course of action (even if it cannot be a
"reasonable" one in any meaningful sense).
[This is the end of this post for the "B" path.]
If we proceed, as we are now doing, it is because we have opted to accept "A," at least provisionally. At any time, we may switch back to "B" and be done with this entire discussion (and with all other logical discussions as well). However, as long as we proceed, we are doing so on the assumption that our thoughts have meaning - and, therefore, that we are potentially able to evaluate the grounds upon which we base our conclusions.
There are a few interesting consequences of this choice. First, it has to be a completely "free-will" decision. If this choice were merely the end result of a chain of causes (because ), then we could not trust it any more than we would be able to trust any other "caused" decision. As long as we choose to follow path "A," we must accept the consequence that "free will" must exist at some level - otherwise this decision would be as meaningless as any choice we might make on the "B" path - we would not really be operating under the "A" assumption.
Next, this choice forces the logical terms "True" and "False" to assume the status of objective facts about the external world. It can be seen that under this choice, it would be "right" to assign the term "True" to logical constructs which deserve that term, and "wrong" to assign the term "False" to those same constructs. In this way absolute values are assigned to a very shallow excursion into the realm of human morality. (Deeper excursions readily follow.)
But, perhaps strangest of all, this choice forces the conclusion that strict causality cannot possibly be the basis of human rationality. Human reasoning must, in some way, transcend the mere chain of causality.
The strict naturalist asserts that his ability to reason is simply the result of the electro-chemistry of his brain - his thoughts no more than a domino-chain of cause and effect. Further, he believes that evolution was the design force which produced that brain. In the coarsest possible terms, this means he believes his brain, and its thoughts, are the end result of a long chain of cosmic causes and effects (because ) - all following the laws of physics (some of these laws being almost completely predictable - others allowing for quite arbitrary outcomes). Whether this sequence of events involved predictable, arbitrary, or both types of events, is not particularly significant; what matters is how the basis (because ) for trusting his thoughts ever came into being.
Naturalistic evolution is often regarded as having superhuman design powers. If enough random combinations are tried, its "monkeys" will flawlessly type any imaginable work of literature. But, unfortunately, mathematics and logic come into play here as well: the odds against typing anything meaningful in this context are worse than merely "astronomical" - they are absolutely preclusive. (And since this is path "A," we are forced to accept the validity of the mathematics and logic which, in turn, force us to that conclusion.)
Furthermore, even the simplest reproducing single-celled organism depends upon an entire "factory" of cellular machinery being in place before evolution can even begin to operate. The DNA molecule assumes the same identical chemical configuration in all forms of life - only its data pattern varies between individuals. The ribosomes (tiny nano-tech, CNC (computer numerical control) machines which follow mRNA templates to chain amino acids together into the necessary complex proteins) are the same in all forms of life. (The technical term for this is "evolutionarily stable.")
What that implies may be a bit of a surprise: If it were possible for evolution to change any piece of these ribosome CNC machines, without breaking them, evolution would have found a way to do it - in the three billion years since life began. The fact that it hasn't says something important about the probability of the entire machine randomly coming into existence in the first place - especially since minor modification is much easier than stepwise design from scratch. Remember that this molecule had a thousand times more time than we presume was required to change the chimp-like brain of Dr. Johansonï¿½s "Lucy" into the brain of a philosopher - a brain which seems to be able to transceend causality itself. (Also, chances to modify ribosomes also involved many times more individuals.)
And this is only the tip of the mathematical "iceberg" separating what is seen in the laboratories, and in the fossil record, from the theories which might free us from the necessity of "invoking" an intelligent designer. There seems to be no viable theoretical path connecting what "is" from what "ought to be" in order to make naturalistic evolution possible.
This is not to say that "evolution," in some form, has not occurred. Evidence from biochemical taxonomy and from the fossils, clearly maps out the path (all of it stasis and quantum leaps - very limited gradualism) that emerging life has followed. Mathematics merely eliminates the possibility that this proven branching process happened under the guidance of random mutations and survival fitness alone - without innumerable critical and extremely intelligent inputs along the way.
And even if naturalistic evolution were possible, (I certainly have not bothered to detail all of the studies to which I carelessly refer here) that would still leave our thoughts as a mere end result of a chain of causality. We would no longer be following path "A" but would, instead, find ourselves back on path "B."
There still remains the question of whether or not the "creator" can be trusted. It would seem that this takes us back to the same arbitrary "A" or "B" choice we made above - about whether or not our own thoughts could be trusted - just substitute "the Creator's design of our minds" for "our own thoughts." Further, the same two (arbitrary) paths which our reasoning might follow will lead us in exactly the same two directions.
For some reason our ancient and ignorant ancestors kept finding convoluted reasons for "inventing" deity in situations where none was necessary; we are justified in identifying this tendency as "alogical" at least - if not simply "illogical." I suppose that this is no more surprising than how we moderns keep inventing reasons to convince ourselves that no deity exists - even where denying the basis of logic itself is the only way to defend this choice. Our ignorant ancestors would have been justified in identifying us moderns as "alogical" at least - if not simply "illogical."
Information and ideas presented in this post are probably mostly stolen or adapted from:
Miracles, C.S. Lewis
1984, George Orwell
Origins, Robert Shapiro
Gödel Escher Bach, Douglas R. Hofstadter
Evolutionary Dynamics, James P. Crutchfield
Mathematics of Evolution, Fred Hoyle