Why am I an atheist? Since atheism is still a somewhat unusual point of view, let me be candid about why I believe no God exists.
Before proceeding, it is important to define God — otherwise no coherent discussion is possible. I define God as “the solitary, perfect, non-physical being who created the physical world.” By non-physical I mean “bodiless, not consisting of matter/energy (as those terms are used by physicists and other scientists).” Here then is an outline of my reasons for rejecting the existence of God, in order of importance:
A) In an argument to the best explanation, naturalism trumps supernaturalism.
My argument here is that a natural world view fits reality and is self-consistent. Supernaturalism (and therefore God) is not needed to explain existence and, more importantly, can’t explain it anyway. Whether we are attempting to account for the existence of human consciousness or the human body, of morality or the value of life, naturalism provides better explanations across the board. I’ve touched on some of these points in Why Are We Alive?, Does Life Have Meaning?, Thoughts, Feelings, & Faith, C. S. Lewis’ Moral Argument, Can General Atheism Be Proved?, The Key to Happiness, and An Irreverent Look at God, Sex, & Design. I’ve laid out the framework of the debate in What Atheists Have in Common and Naturalism’s Touchstone Proposition.
B) God Can’t Exist
B1 – The nature of the physical world makes a non-physical source impossible (the world isn’t something that could have been thought or imagined into existence)
My argument here is that the world is not informational in nature, and does not contain any mental substrate. If so it can’t be thought or conceived into existence. Furthermore, any attempt to define the nature of the physical world in a manner that avoids the impossibility of a creator results in a definition of the physical world which simply does not match reality (see reason A).
Note that a judgment about what physical existence is not lies at the heart of this second argument for atheism. The obvious issue for debate is whether this judgment about the nature of physical existence is correct and therefore whether it is possible for physical things to be conceived or thought into existence — ie, whether it is possible for essence to cause existence. It is my argument that essence is just explanation or description, and neither explanations nor descriptions can cause the physical existence of that which they describe. This represents a rejection of thousands of years of Western thought, yet is supported by modern science as well as arguments as old as the pre-Socratic Zeno of Elea. I have not written much on this yet, but will.
B2 – The nature of God makes creation of a physical world impossible (God has no means to create or interact with physical things)
B3 – The nature of God is incompatible with the particular world we have (God is perfect but the world we have is imperfect)
The argument from perfection, also referred to as the problem of evil, was presented in Agnosticism Revisited and the Case for Atheism (this link should take you to the beginning of the perfection argument within that post).
C) There is insufficient evidence to believe in God or any supernatural world view
Many atheists start with C, implicitly assume A, and hardly touch B (except B3 when considering the problem of evil). Although I consider C the weakest of the three reasons for atheism, it has an important place — especially when considering imperfect gods and deities.
This is only an outline, of course. It’s gradually being fleshed out on this site.