First, if atheism is true, objective moral values do not exist. If God does not exist, then what is the foundation for moral values? More particularly, what is the basis for the value of human beings? If God does not exist, then it is difficult to see any reason to think that human beings are special or that their morality is objectively true. Moreover, why think that we have any moral obligations to do anything? Who or what imposes any moral duties upon us? Michael Ruse, a philosopher of science from the University of Guelph, writes,
The position of the modern evolutionist . . . is that humans have an awareness of morality . . . because such an awareness is of biological worth. Morality is a biological adaptation no less than are hands and feet and teeth . . . . Considered as a rationally justifiable set of claims about an objective something, ethics is illusory. I appreciate that when somebody says ‘Love they neighbor as thyself,’ they think they are referring above and beyond themselves . . . . Nevertheless, . . . such reference is truly without foundation. Morality is just an aid to survival and reproduction, . . . and any deeper meaning is illusory . . . .
As a result of socio-biological pressures, there has evolved among homo sapiens a sort of “herd morality” which functions well in the perpetuation of our species in the struggle for survival. But there does not seem to be anything about homo sapiens that makes this morality objectively true.
Moreover, on the atheistic view there is no divine lawgiver. But then what source is there for moral obligation? Richard Taylor, an eminent ethicist, writes,
The modern age, more or less repudiating the idea of a divine lawgiver, has nevertheless tried to retain the ideas of moral right and wrong, not noticing that, in casting God aside, they have also abolished the conditions of meaningfulness for moral right and wrong as well.
Thus, even educated persons sometimes declare that such things are war, or abortion, or the violation of certain human rights, are ‘morally wrong,’ and they imagine that they have said something true and significant.
Educated people do not need to be told, however, that questions such as these have never been answered outside of religion.
He concludes,
Contemporary writers in ethics, who blithely discourse upon moral right and wrong and moral obligation without any reference to religion, are really just weaving intellectual webs from thin air; which amounts to saying that they discourse without meaning.