My definition comes from exactly how the word was created. A, a prefix meaning “not” and theism, meaning “the belief that god or gods exist”, atheism is “not” – “the belief that god or gods exist”. It is “not theism”, it is just like “not red” or “not forward”.
Not quite correct, chris. "Atheism" is any belief which is not "theism", it is not a held view point unto itself. There are many different types of atheist, among them the "there is no god" and the "I have no belief in god" stances.
Sorry, lads, but I have to disagree with you with regards to the etymological argument. The word "atheism" consists of three components:
- the prefix "a-" from the Greek prefix meaning "no" (in the sense of "none") or "not";
- the root "-the-" from the Greek "theos" meaning "god"; and
- the suffix "-ism," derived from the Greek suffix "-ismos," initially "used to form a noun of action from a verb" as Wikipedia puts it.
Now, your claim is that the prefix "-a" reflects on the root and suffix combined, i.e. "atheism" is "not godism." I'm inclined to think that the prefix reflects on the root alone, i.e. "atheism" means "no god-ism," the positive belief that there is no god, and indeed, various other posters have cited references pointing out that this was, indeed,
originally what "atheism" meant. Compare the adjective "athanatos": going by the components, you might read it to mean simply "not dead," but it actually means "immortal." "No death" rather than "not (yet) death." It's not entirely analogous, but it gives you an idea.
However, I stress the word "originally" because this is a good example of how the usage of a word can drift away from its etymological origins. "Atheism" may originally have meant "the positive belief that there are no gods," and it still does mean that, but these days, it is also commonly used to include,
in addition to its original meaning, the simple lack of positive belief that one more gods do exist.
As another example, take the Saxon word
huscarl. These days, it's only used by military historians, and it refers to members of Saxon nobles' personal guards; they were better equipped, armored and trained than the rank and file, and are considered to be the "élite" of any Saxon army, such as the one that faced William the Conqueror's Normans at Hastings in 1066. But the original meaning of the word can be divined from the most literal translation into modern English: "house churl." These were members of the lowest social rank of freemen (and as such, they still ranked above slaves) who were employed by a noble as domestic servants. No noble, not even the king, could afford to keep a guard of professional soldiers on hand full time, so he kept weapons and armor on hand and had his tougher stable hands and whatnot trained in their use, and in the event of war, he formed them into his personal guard. The same process explains how a common Germanic root became
Knecht ("servant, hired hand") in German, and
knight in English.
Riiight. 
