You have probably heard about the multiverse--the idea that the universe is really a large number of universes. The multiverse helps to explain why our particular universe seems so special. Our universe seems to be a finely tuned machine and the evolution of life would require low probability events. Is our universe special? The multiverse helps to deflect such thinking. If there is a large number of universes, then perhaps each has a different set of natural laws. And perhaps intelligent life can only be supported by a very particular set of laws. So the only life forms that would exist to observe their universe would be those that live in special universes. Presto, we're not special and fine tuning and evolution are explained.

There is, however, another type of fine tuning that evolutionists have not explained. In addition to physics and biology, philosophy is also fine-tuned. I suspect it can also be explained with the multiverse, but we need to start keeping a list of all the little things we sweep under the multiverse rug. Philosophy is fine-tuned in the sense that evolutionary theories of origin are both (i) fact and (ii) intellectually necessary. Let me explain.

On the one hand, evolutionists say they know that evolution (of one sort of another) is a fact, every bit as much as gravity is a fact. Life and all the species arose strictly by purely naturalistic processes. If you doubt this, it is equivalent to doubting the existence of gravity. It is remarkable that evolutionists have this level of certainty, but keep in mind they are very smart people.

On the other hand, evolutionists say that evolution (again, of one sort of another) must be assumed in order to do science. We saw how evolutionary thinkers, from the Joseph LeConte in Darwin's day to PZ Myers today, have illuminated this requirement. Here is another example from another evolutionist, Barbara Forrest:

Intelligent design creationism (ID) is a religious belief requiring a supernatural creator’s interventions in the natural order. ID thus brings with it, as does supernatural theism by its nature, intractable epistemological difficulties. ... I examine the ID movement’s failure to provide either a methodology or a functional epistemology to support their supernaturalism, a deficiency that consequently leaves them without epistemic support for their creationist claims.

In other words, in order to avoid "intractable epistemological difficulties" and get along with the business of doing science, evolution is a must. So, evolution is both a fact and intellectually necessary. These are two independent properties. It didn't have be this way. We could live in the universe where evolution is not a fact, but yet intellectually necessary. Or we could live in the universe where evolution is a fact, but yet not intellectually necessary. Either way things would be very confusing. I'm glad we're not stuck in one of those universes. Thanks to the multiverse, there are options. We live in a universe that is finely-tuned for truth, and full of evolutionists to explain this to us.

As a follow-up to his earlier comments that design is not a legitimate scientific hypothesis, evolutionist Joe Felsenstein adds this comment:

Thanks to Cornelius Hunter for quoting my comment at Panda's Thumb in its entirety, without emendation (he did add some emphasis, in color, but not in a way that changed my meaning).

My comment was not responsive to the origin of T-urf13 but was intended as a response to many other comments Hunter has made on this blog (and at Uncommon Descent) in which he argues that one cannot predict what a Designer would do, and thus that arguments that she would not make bad design are invalid.

As should be clear from my statement, I was pointing out that this makes the hypothesis of a Designer not a scientific theory, and thus not a credible alternative to naturalist explanations.

Oh, and it should be clear that naturalism does *not* create an "intellectual necessity" of evolution. There are explanations that might be advanced that are not evolutionary but are natural. It is the evidence, not simply naturalism itself, that is the basis for concluding that life has evolved.

Unfortunately these misrepresentations are typical of evolutionists. Not only are evolution's metaphysical arguments from dysteleology, or bad design, perfectly valid, they can also be quite powerful. Felsenstein's strawman that we say otherwise would be bizarre if it wasn't so common.

Next Felsenstein explains that his message is that he thinks that the hypothesis of a Designer is "not a scientific theory, and thus not a credible alternative to naturalist explanations."

Yes, that is precisely the point. The intellectual necessity is a metaphysical argument for naturalistic explanations. As with all the dozen or more metaphysical mandates for evolution, the argument attacks design or creation using non scientific premises that a design or creation advocate would not recognize.

Felsenstein next writes that "naturalism does *not* create an "intellectual necessity" of evolution." Of course it doesn't and it is a wonder that Felsenstein arrived at such a backward reading. The mandates for naturalism and evolution come from religious and philosophical traditions entailing non scientific premises.

Evolutionists consistently mischaracterize criticism to convert serious problems into so many strawmen to knockdown.

Finally Felsenstein appeals to the evidence. Evolutionists are notorious for their claims that the science proves evolution to be a fact. But such proofs always rely on metaphysics. The number of evolutionists who have explained how the science proves evolution is precisely zero.

And, to forestall the usual response, no one is misunderstanding what "fact" means. Evolutionists say their theory is a fact as much as is gravity or the round shape of the earth. That is an absurd claim which, not surprisingly, has never been justified scientifically.

I have tremendous respect for Felsenstein's smarts as a scientist and the quality of his work. But so often we see world-class scientists appear foolish propping up evolution. Religion drives science and it matters.

Evolutionist Joe Felsenstein sounded a familiar note recently when he appealed to evolution's intellectual necessity in response to scientific criticism. I pointed out here that the blind evolution of the de novo gene T-urf13 is highly unlikely. In typical fashion, the evolutionist completely ignored the scientific issue at hand and skipped straight to the metaphysics. There are about a dozen metaphysical arguments mandating evolution. They fall into the two categories of theology and philosophy and provide the foundation of evolutionary thought going back several centuries. You can see my reconstruction of the evolution of evolutionary thought here. There is much cross fertilization between these traditions which form a sort of tapestry in the history of thought. Of course these arguments are not scientific, but they are extremely powerful. They are why evolutionists confidently know their theory must be true. Therefore empirical evidence is not an epistemological problem, but merely a scientific problem. No observation can harm our knowledge that evolution is a fact. Hence Felsenstein goes straight to the underlying philosophy:

A simple way to state the problem with Cornelius Hunter’s argument is that he is arguing that a Designer could do anything, so a Designer cannot be refuted by any observation. He is happy to have thereby refuted all the people who point out bad design.

But he doesn’t get it that what he has just done is to admit that the hypothesis of a Designer is not science, as it predicts every possible result. If you predict every possible outcome, the ones that are seen and the ones that are not, then you have not predicted anything!

Unless you have some information about the Designer’s intentions, her powers, how frequently she acts, and where, and on which organisms and which phenotypes, you ain’t got nothin’, no scientific hypothesis at all.

In other words, not only is evolution true, it also is necessary for proper science. That's convenient.

This argument that strictly naturalistic explanations are mandated in the historical sciences traces back to the nineteenth century before Darwin though, as with several of evolution's metaphysical planks, it gained momentum from Darwin's theory as much as it fueled Darwin's theory in the first place.

Darwin's main concern was that people accept evolution. Which subhypothesis of evolution one accepts, explained Darwin, "signifies extremely little in comparison with the admission that species have descended from other species, and have not been created immutable: for he who admits this as a great truth has a wide field open to him for further inquiry."

Evolution was needed for scientific research as that was yet another spot where creation failed. As he wrote in Origins:

On the ordinary view of the independent creation of each being, we can only say that so it is;—that it has pleased the Creator to construct all the animals and plants in each great class on a uniform plan; but this is not a scientific explanation.

As Darwin’s friend J. D. Hooker put it, if theories of divine creation are "admitted as truths, why there is an end of the whole matter, and it is no use hoping ever to get any rational explanation of origin or dispersion of species—so I hate them."

Thirty years later evolutionist Joseph Le Conte argued that the origins of new species, though obscure and even inexplicable, must have a natural cause. To doubt this, he warned, is to doubt "the validity of reason, and the rational constitution of organic Nature." For Le Conte divine creation was not rational. Evolution, he triumphantly concluded, "is as certain as the law of gravitation. Nay, it is far more certain."

Needless to say this metaphysical sentiment only grew stronger in the twentieth century. Evolutionists, under the guise of science, continued to issue this non scientific mandate for evolution. As Niles Eldredge wrote more recently:

But the Creator obviously could have fashioned each species in any way imaginable. There is no basis for us to make predictions about what we should find when we study animals and plants if we accept the basic creationist position. … the creator could have fashioned each organ system or physiological process (such as digestion) in whatever fashion the Creator pleased.

Felsenstein's metaphysic is nothing new. It falls into well defined clade in the history of evolutionary thought. Of course there is nothing wrong with metaphysics, per se. But let's not pretend we're doing science.