Secular humanism and atheism are not identical. One can be an atheist and not a secular humanist or humanist. Indeed, some thinkers or activists who call themselves atheists explicitly reject humanist ethical values (for example, Stalin, Lenin, Nietzsche, and others). Nor is secular humanism the same thing as humanism by itself; it is surely sharply different from religious humanism.
[S]ecular humanism is not antireligious; it is simply nonreligious. There is a difference. Secular humanists are nontheists; they may be atheists, agnostics, or skeptics about the God question and/or immortality of the soul. To say that we are nonreligious means that we are not religious; ours is a scientific, ethical, and philosophical life stance. I have used the term eupraxsophy to denote our beliefs and values as a whole. This means that, as secular humanists, we offer good practical wisdom based on ethics, science, and philosophy.
The term secular should make it clear that secular humanists are not religious. In contrast, the term religious humanism is unfortunate. It has been used by some humanists to denote a kind of moral and æsthetic commitment to a set of ideals and practices; but this is most confusing. Often it serves to sneak in some quasi-spiritual and/or transcendental aspect of experience and practice, aping religion.
It is puzzling that religiosity is so strong in America today and that even humanists are fearful of denying that they are nonreligious. In my view, cowardice is an important motive for many religious humanists who are embarrassed for anyone to know that they do not believe in God or salvation; and so they fudge, hide, mask, and obfuscate their real convictions in order to be socially accepted. They fear especially to be seen criticizing religion or to become known as an atheist. Ecumenism teaches that we should accept virtually all religions. In that spirit of tolerance, religious humanists do not wish to be seen as critical of any religion, whether Roman Catholicism, Islam, Judaism, or the numerous denominations of Protestanism.
Secular humanism is thus committed to science and reason as the method of evaluating all truth claims, whether arising in popular belief, scientific theories, or in moral, political, or religious claims. Similarly, secular humanists are sympathetic to skeptical inquiry--that is, the application of rational methods and empirical/experimental testing to all claims to truth. For that reason, too, secular humanists cannot understand why religious humanists so fear to step on the toes of their religious brethren. Similarly, secular humanists are critical of those contemporary skeptics who express trepidation about treading in religious waters. Surely, skeptical epistemology means that there is open season on any and all claims to truth; all are subject to empirical and rational scrutiny. Critical thinking should not be confined to paranormal claims alone, which might be considered safe to criticize. In principle, critical thinking should likewise be applied to religion, politics, economics, and morality.
What is central to humanism, in my view, is the ethical component; namely, humanists believe that:
Ethics is an autonomous field of inquiry, independent of theological claims, amenable to rational scrutiny, testing value judgments by their consequences. Ethical values and judgments are relative to human interests, needs, desires, ends, and values; they are open to objective criticism and evaluation.
Fulfillment, realization, and maximization of human freedom and happiness are what humanists seek, both for the individual and the community.