Originally Posted by radix
In point of fact they are both agnostic, not atheist.
There are a lot of semantic debates on the meaning of those words. Atheist, to many, just means lack of belief in the claim that god(s) exist. Without Theism. Agnostic really has more to do if you think that it is even knowable.
Either way, Buffet & Gates have no religion, and hold no belief in any kind of God that cares about human affairs. Their charity is based entirely on secular reasons, which was my point.