This is precious:
An atheist, in my understanding (and Messrs Merriam and Webster’s), is a person who denies that there is a God. You can deny that there is a God and yet believe in a whole ontinuum of supernatural critters, from everyday (-night?) ghosts up to the angels. You seem to be using “atheist” to mean “a person who denies the supernatural.” That would be a “naturalist,” or colloquially a “materialist.” [John Derbyshire]
First, Derbyshire makes an error by attributing his personal views to some kind of dictionary authority. Merriam-Webster’s 11th Collegiate Dictionary refers to “a disbelief in the existence of deity” and “the doctrine that there is no deity”; it later defines deity as either “the rank or essential nature of a god,” “supreme being,” “a god or goddess,” or “one exalted or revered as supremely good or powerful.” The wording in Merriam-Webster’s Collegiate is just a condensed version of the wording in Webster’s Third New International.
Clearly, Derbyshire intends to take the position of the traditional European atheist, who may be culturally religious and merely opposes monarchical theism on principle. This position makes a mockery of the modern atheism that claims positive knowledge of the structure, history, and fate of the entire universe through the magic of “scientific materialism.” This modern, positivistic atheism is transparently nothing more than a soulless, mechanistic, and idealistic form of humanism.
Derbyshire also makes the common error of stating that “a person who denies the supernatural” is a “naturalist,” and that a colloquial synonym is “materialist.” However, a naturalist would properly be one who accepts whatever is found in nature, including human society; and human society includes many who attest to the existence of supernatural forces or beings. Also, the naturalist would not seek to impose any ideal upon nature by claiming that any particular unobserved phenomenon could not occur.
The dogmatic materialist, on the other hand, asserts that all of nature follows an ideal form in which unexplainable phenomena cannot occur at all. The other difference between the naturalist and the materialist consists in how phenomena are explained; for a materialist may be infinitely reductive and mechanistic, whereas a naturalist would allow for growth and change according to an organic potentiality, as well as unforeseeable complex interactions.
Some atheists claim that through scientific knowledge they come necessarily to the logical conclusion that everything is reductively explainable and that there is nothing supernatural. But that is not the same as Derbyshire’s opposition to a supreme, personal, monarchical deity; nor is it the same as the liturgical, religious, ascetic contemplation of a monk who reveres a transcendant human; nor is it a form of philosophical naturalism. Such an atheism is rather a pathological, idealistic egotism, which unsurprisingly manipulates tribalism in order to facilitate unrepentant mass murder.
So, are egotism and tribalism irrational? What about the everyday activities of the average person, who unthinkingly eats and talks and performs non-ideal bodily functions? These are only irrational in comparison to some kind of mathematical or “scientific” abstraction of human rationality, an ideal model of human thinking that is entirely contrived and lacking any basis in the natural world.