Many atheists around the world today define atheism, in the words of an atheist, as the "lack of belief in a god or gods". But, is this what atheism really means? Well, let's take a look at where the word "atheist" comes from and what it meant. We'll also examine whether or not the atheist bears a burden of proof as this ties into this particular discussion.

The word "atheist" is Greek in origin. The word derives from the Greek prefix "a", which means "no", and the Greek suffix "theos" which means "god", to get the word "a-theos". Directly translated, the word "a-theos" means "no god". The Greek suffix "ism" was later added onto the word for it to become "a-theoism", or, "atheism". "ism" is added on so that the word can become a noun and then be attributed to a human. So, the word "atheism" *technically* means that you assert the nonexistence of a god or gods. The word originally meant that you believe that there are absolutely no gods.
The following definition of atheism comes from Dictionary.com: 1.) "The doctrine or belief that there are no gods."
2.) "Disbelief in the existence of a supreme being or beings."
The definition from my Webster's 21st. Century dictionary is the as follows: "Belief that no god exists."
So, we have discovered that atheism isn't really the lack of belief in any god(s), but more than that. It is the belief or the assertion that a god or gods do not exist and never have or will. Also, another dispute between atheists and Christians is whether or not atheism is a belief system. It is. As you can see from the definition of atheism, it is the *belief* that there exists absolutely no god(s). This affirms atheism as a belief system, no different than theism. Now, let's discuss why atheism is different than agnosticism, and how.

Agnosticism, as defined by Dictionary.com is as follows: "An intellectual doctrine or attitude affirming the uncertainty of all claims to ultimate knowledge." The definition from my Webster's 21st. Century dictionary defines "agnostic" as: "A person regarding the existence of God as unknowable." What this means is that agnosticism is, essentially, the withholding of any belief in God on the basis that one cannot ultimately know. It differs from atheism in that atheism directly asserts the non-existence of God, and this is why the burden of proof also lies on the atheist and we're going to discuss why.

Atheism bears a burden of proof because it makes an assertion which requires some form of affirmation, such as evidence. If you claim that you cannot draw any evidence for the nonexistence of God based on the notion that "you can't prove a negative", then your dodging the question, because nobody asked you to *prove* atheism as true. The atheist was asked to provide evidence not *for* the nonexistence of God, but to provide evidence *against* the existence of God, thusly, the atheist does, indeed, bear a burden of proof. You wouldn't be proving a negative, but disproving a potential positive. Anytime an assertion is made, you must provide evidence in support of this assertion. If you are not asserting that God does not exist, then you are not claiming atheism, you are claiming agnosticism. You are, then, merely withholding your belief in the existence of God rather than asserting that He does not exist.
The atheist bears a burden of proof because he, as an atheist, makes an assertion and, therefore, must provide support/evidence of said assertion.