Criticism of atheism is criticism of the concepts, validity, or impact of atheism, including associated political and social implications. Criticisms include arguments based on theistic positions, arguments pertaining to morality or what are thought to be the effects of atheism on the individual, or of the assumptions, scientific or otherwise, that underpin atheism. Criticism of atheism is complicated by the fact that there exist multiple definitions and concepts of atheism (and little consensus among atheists), including practical atheism, theoretical atheism, negative and positive atheism, implicit and explicit atheism, and strong and weak atheism, with critics not always specifying the subset of atheism being criticized.