It’s sometimes said that the atheist has nothing to defend, being that they have a only a common disbelief and not a system of belief demanding a defense.
This approach would be inadequate for many reasons, not the least of which would be the problem of the “commoness” of cultural Atheism. Atheism can take on characteristics traditionally reserved for the description of religious systems with its own peculiar and common dogmas, communities, conversions, and sacred texts. The arguments and beliefs common to the system provide an identifiable ideological center. The cosmos as all that is, all that was and all that will ever be, can be a rather strict standard of orthodoxy. There are also available means for the enforcement of orthodoxy at the community, academic and professional levels of social stratification.
More obvious is a common core of belief that tends to be supported by common sets of arguments: 1) Arguments for the superiority of naturalism and refutation of the classical arguments for the existence of God. 2) Arguments for the superiority of atheistic morality and against the morality of theism. 3) Arguments for the superiority of the mental state of atheists and against the psychological well being of adherents to religion. 4) Arguments for the superior sociology of atheism and against the social benefits of religion. 5) Arguments for the superiority of empiricism, rationalism and the exclusivity of the scientific method and against general and special revelation. These together represent an established ideological core, which for the most part, is held as a worldview or system of belief that can be weighed, measured and found true or false on the basis of the available evidence.
Statements such as that the cosmos is all that is, all that was and all that will ever be, are of course faith statements and not conclusions rooted in argument or evidence, but they represent the center of the system and so are open to refutation, not from within the system itself, as adherents to the system have set up epistemological and sociological self protections, but through showing internal self contradiction and truths contrary to those within the system itself.