Secular humanists affirm that with the present state of scientific knowledge, dogmatic belief in an absolutist moral or ethical system (e.g. Kantian, Islamic, Christian) is unreasonable. However, it affirms that individuals engaging in rational moral/ethical deliberations can discover some universal "objective standards". Many humanists adopt principles of the Golden Rule. Some believe that universal moral standards are required for the proper functioning of society. However, they believe such necessary universality can and should be achieved by developing a richer notion of morality through reason, experience and scientific inquiry rather than through faith in a supernatural realm or source. Humanists Andrew Copson and Alice Roberts, in their casual introduction to humanism The Little Book of Humanism, propose that a distinctive aspect of humanist morality is its recognition that every moral situation is in some sense unique, and so potentially calls for different approach than the last (i.e. the ability to vacillate situationally between consequentialism and virtue ethics). In the book, they quote from Kristen Bell's advocacy of moral particularism as developed by Jonathan Dancy. Humanism is compatible with atheism, and by definition usually entails at least a form of weak or agnostic atheism, and agnosticism, but being atheist or agnostic does not automatically make one a humanist. Nevertheless, humanism is diametrically opposed to state atheism. According to Paul Kurtz, considered by some to be the founder of the American secular humanist movement, one of the differences between Marxist–Leninist atheists and humanists is the latter's commitment to "human freedom and democracy" while stating that the militant atheism of the Soviet Union consistently violated basic human rights. Kurtz also stated that the "defense of religious liberty is as precious to the humanist as are the rights of the believers". Greg M. Epstein states that, "modern, organized Humanism began, in the minds of its founders, as nothing more nor less than a religion without a God". Many humanists address ethics from the point of view of ethical naturalism, and some support an actual science of morality. Modern context Secular humanist organizations are found in all parts of the world. Those who call themselves humanists are estimated to number between four and five million people worldwide in 31 countries, but there is uncertainty because of the lack of universal definition throughout censuses. Humanism is a non-theistic belief system and, as such, it could be a sub-category of "Religion" only if that term is defined to