Many modern people hold a combination of religious or metaphysical beliefs and also generally approach the world scientifically and trust what the scientific community tells them. I think these two points of view are ultimately incompatible.

First, I believe that the scientific method is the best known method for making accurate predictions about the current and future state of the world. This is not to say that there is not some unknown, better method. If some better method were developed, it would replace the scientific method: not just because the people who rely on the scientific method (far more than just the scientific community) would realize its superiority, but also because the scientific method itself would dictate the adoption of this new method.

Second, I believe that Occam’s Razor is a very good rule of thumb when applying the scientific method to a problem.

Our universe cannot include a god, spirits, souls, or even any intrinsic “right and wrong” or other guiding metaphysical principles. If any of these things were to exist, and have an effect on the physical world, then at some point their influence would manifest physically. Assume for the sake of argument that god existed wholly and completely metaphysically, outside the scope of the physical world. If that god wanted to manipulate our universe somehow, he, she or it would have to ultimately cause an event in the physical world. In other words, he, she or it would have to make a neuron fire inexplicably, a particle disobey gravity, a photon travel slower or faster than the speed of light, and so on. This crossing over between the metaphysical and the physical would manifest as a violation of the known laws of physics, since the known laws of physics (even the statistical laws of quantum mechanics) totally determine the behavior of physical systems.

The physical sciences have come upon many strange and mysterious phenomena over hundreds of years of study. But never, in that time, has any phenomena steadfastly refused explanation. Therefore, there is no evidence yet for the metaphysical. The scientific method does not consider explanations without evidence, so god or anything else metaphysical as an explanation for any processes is not an valid explanation.

A metaphysical explanation of anything is also in serious violation of Occam’s Razor. Proposing the existence of a metaphysical influence to explain some unexplained phenomena adds vast complexity to our system of knowledge about the world. So why even consider going down that path when Occam’s Razor has served us so well for so long?

Even a god who is merely a powerless observer of our world would have to interact with it in some physical way to perform that observation. Some photons must be detected, some sound waves absorbed, some magnetic or gravitational fields measured. And even this observation would use up energy and be eventually detectable.

The transfer of any or all aspects of our personalities to an afterlife or reincarnation also would involve a transfer of energy or matter between the physical realm and some metaphysical realm, so even it would be detectable. Similarly, the existence of a “soul” that represents some aspect of our consciousness independent from our physical brain would require a mechanism for that soul to manifest physically in the brain. So even the idea of a “soul” is a staggeringly complex system in search of unexplained observations.

Nothing I have said rules out a “god” which is part and parcel of the physical world. In other words, “god” could turn out to be a super-intelligent space alien with a technology vastly beyond ours, indistinguishable to our uneducated eyes from magic. But this “god” is not really a religious god, except maybe in its behavior. It is not outside eventual explanation through the scientific method, and not necessarily permanently beyond human comprehension. And it is not ultimate; nothing precludes these super-intelligent space aliens from encountering even more intelligent and technologically advanced beings who to them appear godlike.

And the super-intelligent space aliens explanation also violates Occam’s Razor, although not as seriously — positing the existence of super-intelligent space aliens is not a simple explanation for anything as yet unexplained. So even that explanation goes to the bottom of the list, and stays there until all the more likely explanations are discounted.

Also, nothing I have said rules out a “god” who is simply a first mover — a god who set everything in motion back before the Big Bang and then stepped back to let things take their course. But the theoretical physicists who are exploring the early days of the universe have not yet needed to propose the existence of a god to explain a first cause. So, again, this explanation goes at the bottom of the list.

The scientific community in this country spends a lot of energy trying to assuage the fears of our largely religious population about the obsolescence of religon, and trying to convince everyone that science and religion can coexist in the modern world. While I realize the current political utility of this stance to the minority of scientific thinkers in a religious political environment, it is ultimately untenable. Science and religion are not compatible. Belief in the metaphysical world and in god is obsolete, and I look forward to a world where the scientific method prevails.