The distinction between atheist and anti-theist lies in their attitudes toward belief in God or gods.

Atheist. An atheist is someone who simply does not believe in the existence of a God or gods. Atheism is about a lack of belief, and it can range from passive non-belief to active disbelief, but it does not necessarily imply opposition to religion itself or to religious beliefs.

Anti-theist. An anti-theist, on the other hand, goes a step further. In addition to not believing in God or gods, an anti-theist actively opposes religion and religious belief. This stance often arises from the view that religion is harmful or detrimental to individuals or society. Anti-theists may be outspoken critics of religious institutions and practices, viewing them as misleading or morally problematic.

So, while all anti-theists are atheists, not all atheists are anti-theists.

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