Recently my friend and colleague in science and skepticism Neil deGrasse Tyson, issued a public statement via BigThink.com in which he stated that he dislikes labels because they carry with them all the baggage that the person thinks they already know about that particular label, and thus he prefers no label at all when it comes to the god question and simply calls himself an agnostic.

I have already written about this many times over the decades, and my 1999 book How We Believe outlines in detail why I too hate labels. In fact, in my later book, The Mind of the Market, I explained why I also do not like the label “libertarian” because people automatically think this means believing something that I very likely do not believe (e.g., that humans are by nature purely selfish, that we have no moral obligation to help others in need, that greed is the only motive that counts in business, and that Ayn Rand was actually the Messiah), and instead I prefer to go issue by issue. Nevertheless, the label “libertarian” and “atheist” stick, and as I explained in my latest book, The Believing Brain, I’ve largely given up the anti-label struggle and just call myself by these labels. In effect, what I once thought of as intellectual laziness on the part of my interlocuters who did not seem to want to bother to actually read my clarifications and what, exactly, I do believe about this or that issue, I now see as the normal process of cognitive shortcutting. Time is short and information is vast. Most of the time our brains just pigeonhole information into categories we already know in order to move on to the next problem to solve, such as why not one Mexican restaurant band I have ever asked seems to know one of the greatest Spanish pieces ever produced: Malagueña. It’s a riddle wrapped in a mystery inside a tortilla.

Still, it is worth thinking about what the difference is between atheist and agnostic. According to the Oxford English Dictionary: Theism is “belief in a deity, or deities” and “belief in one God as creator and supreme ruler of the universe.” Atheism is “Disbelief in, or denial of, the existence of a God.” Agnosticism is “unknowing, unknown, unknowable.”

Agnosticism was coined in 1869 by Thomas Henry Huxley to describe his own beliefs:

When I reached intellectual maturity and began to ask myself whether I was an atheist, a theist, or a pantheist…I found that the more I learned and reflected, the less ready was the answer. They [believers] were quite sure they had attained a certain ‘gnosis,’—had, more or less successfully, solved the problem of existence; while I was quite sure I had not, and had a pretty strong conviction that the problem was insoluble.

Of course, no one is agnostic behaviorally. When we act in the world, we act as if there is a God or as if there is no God, so by default we must make a choice, if not intellectually then at least behaviorally. To this extent, I assume that there is no God and I live my life accordingly, which makes me an atheist. In other words, agnosticism is an intellectual position, a statement about the existence or nonexistence of the deity and our ability to know it with certainty, whereas atheism is a behavioral position, a statement about what assumptions we make about the world in which we behave.

When most people employ the word “atheist,” they are thinking of strong atheism that asserts that God does not exist, which is not a tenable position (you cannot prove a negative). Weak atheism simply withholds belief in God for lack of evidence, which we all practice for nearly all the gods ever believed in history. As well, people tend to equate atheism with certain political, economic, and social ideologies, such as communism, socialism, extreme liberalism, moral relativism, and the like. Since I am a fiscal conservative, civil libertarian, and most definitely not a moral relativist, this association does not fit me. The word “atheist” is fine, but since I publish a magazine called Skeptic and write a monthly column for Scientific American called “Skeptic,” I prefer that as my label. A skeptic simply does not believe a knowledge claim until sufficient evidence is presented to reject the null hypothesis (that a knowledge claim is not true until proven otherwise). I do not know that there is no God, but I do not believe in God, and have good reasons to think that the concept of God is socially and psychologically constructed.

The burden of proof is on believers to prove God’s existence—not on nonbelievers to disprove it—and to date theists have failed to prove God’s existence, at least by the high evidentiary standards of science and reason. So we return again to the nature of belief and the origin of belief in God. In The Believing Brain I present extensive evidence to demonstrate quite positively that humans created gods and not vice versa.