Intelligent design arguments typically don't number more than a handful and most of them are obviously flawed, such as those that take the form of "I find your claim hard to believe and believe that a magic man in the sky is more believable". Obviously it is invalid to presume that something that has not been shown to be possible is "more likely" than anything else. However, what I'll address here is the so called "argument from design" since this is typically the main (if not the only) argument for ID enthusiasts. Argument from design is certainly a consideration of probability which we require inductive logic to adequately address. The argument presented by ID enthusiasts is that an existent universe designer would design universe(s) and that/those universe(s) would be "ordered" and probably contain life (as an example of order) for instance. That is, the probability of "order" given an existing universe designer is higher than the probability of "order" given no existing universe designer, or... 1. pr(o|d) > pr(o|~d) (Where 'o' represents 'order' and 'd' represents 'universe designer'.) But this is obviously a flawed argument. We are not concerned with the probability of "order" (since "order" can loosely be called a tautological description of our universe's existence), but rather we are concerned with the probability of a universe designer instead. That is, the claim that the probability of a universe designer given that there's order is more probable than no existing universe designer given that there's order, or... 2. pr(d|o) > pr(~d|o) Expression 2 is the inverse (or "converse" if you will) of expression 1. Yet the ID enthusiast only observes and can demonstrate an "ordered universe" not any sundry "designer" of universes. So he's "stuck" with expression 1 and needs to validly arrive at (and prove true) expression 2 to have a viable argument. So, how do we get from expression 1 to expression 2? Even if we concede the idea that the probability of an ordered universe given the existence of a universe designer is high, it does not mean that the probability of the existence of a universe designer is high if there is an ordered universe. This is true just like in the case where if I see a Tasmanian Devil in the wild I'm probably in Tasmania, but if I'm in Tasmania I'm probably NOT going to see a Tasmanian Devil in the wild. There is a conversion expression that will get us from expression 1 to its converse, expression 2. And that is... 3. pr(a|b) = pr(b|a) x pr(a)/pr(b) (Just argument's sake, let's just for a moment consider the probability of a universe designer is not 0, otherwise division by zero will give us an indefinite situation and since any 'designer' if you will, would be impossible in that case, the matter would then be moot). When applied to expression 1 it gives us... 4. pr(d|o) x pr(o)/pr(d) > pr(~d|o) x pr(o)/pr(~d) Canceling the pr(o) on both sides gives us... pr(d|o)/pr(g) > pr(~d|o)/pr(~d) Rearranging the equation gives us... 5. pr(d|o)/pr(~d|o) > pr(d)/pr(~d) Notice that expression 2 that we looked at earlier... " 2. pr(d|o) > pr(~d|o) " ...can also be expressed as.... pr(d|o)/pr(~d|o) > 1 Notice how this equivalent expression of number 2 is the same as the first part of expression 5. Now to get from expression 5 to expression 2, we need the latter part of expression five to be true also, or... pr(d)/pr(~d) > or = 1 That is, that the probability of the existence of a universe designer is more likely than or equal to the probability of no existing universe designer. We would have to know this as a matter of "prior knowledge" to the current consideration. We would have to know this via a means OTHER THAN by presuming such a designer's existence from observing an "ordered" universe. Since any universe designer is unprecedented and not known to be Pr (d) > 0 (even possible), then we cannot satisfy what is required to get from expression 1 to expression 2. Therefore, "order" cannot prove nor suggest that there is an existing universe designer. What if the IDer STARTS with expression 2 to begin with, or... " 2. pr(d|o) > pr(~d|o)"? Well expression 2 says that the probability of a designer given an ordered universe is greater than the probability of no existing universe designer given an ordered universer. He or she is STILL in the situation of having to validate the idea that any universe designer is possible, or P(d) > 0. Until then, it would be improper to suggest that any such designer is possible, (zero probability, of course, means a zero chance of occurance or "impossible"). It would be improper because that expression has no earned merit. It is not proven to be true. Do ID arguments strengthen the idea that the existence of a universe designer is more probable than no existing universe designer? JUST THE OPPOSITE in fact. Consider, if we don't know what number a pair of dice fell on, and we randomly guess, is it more likely to be seven or not seven? It's more likely to be not seven because there are six ways to roll a seven and 30 ways to not roll a seven. It's likewise for ID arguments supposedly in favor of an intelligent universe designer. Their arguments MAKE THE POINT that an "ordered" universe can be expected to be much rarer than the alternatives and that this begs the conclusion of a designer, but if the existence of a universe designer would necessitate a designed universe, and since we can see from the above consideration that "order" cannot itself justify the idea of ID, then we can see that there are "more ways" for there to not be a universe designer than for their to be a universe designer just as any given roll of a pair of dice is likely not a roll of seven. In other words, the IDers argument that the "ordered" universe is rare has a complementary argument that a disordered universe would be more expected or more common and since our "ordered" universe does not itself reflect on whether or not there is a universe designer, then the IDers complement argument is that a universe designer is unlikely, thus defeating any assertion that the latter half of expression 5 above has a value greater than 1. Intelligent Design proponent's arguments defeat themselves. LOGOS |
| Proof that ID arguments defeat themselves. |
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| (With all due kudos to logic professor Graham Priest for this line of reasoning) |