Humanism is a broad category of ethical philosophies that affirm the dignity and worth of all people, based on the ability to determine right and wrong by appealing to universal human qualities, particularly rationality. It is a component of a variety of more specific philosophical systems and is incorporated into several religious schools of thought. Humanism can be considered the process by which truth and morality is sought through human investigation. In focusing on the capacity for self-determination, humanism rejects the validity of transcendental justifications, such as a dependence on belief without reason, the supernatural, or texts of allegedly divine origin. Humanists endorse universal morality based on the commonality of the human condition, suggesting that solutions to human social and cultural problems cannot be parochial.

Religion

Humanism clearly rejects deference to supernatural beliefs in resolving human affairs but not necessarily the beliefs themselves; indeed some strains of Humanism are compatible with some religions. It is generally compatible with atheism and agnosticism but doesn't require either of these. The word "ignostic" (American) or "indifferentist" (British, including OED) are sometimes applied to Humanism, on the grounds that Humanism is an ethical process, not a dogma about the existence or otherwise of gods; Humanists simply have no need to be concerned with such questions. Agnosticism or atheism on their own do not necessarily entail Humanism; many different and sometimes incompatible philosophies happen to be atheistic in nature. There is no one ideology or set of behaviors to which all atheists adhere, and not all are humanistic.

As Humanism encompasses intellectual currents running through a wide variety of philosophical and religious thought, several strains of Humanism allow it to fulfill, supplement or supplant the role of religions, and in particular, to be embraced as a complete life stance. For more on this, see Humanism (life stance). In a number of countries, for the purpose of laws that give rights to "religions", the secular life stance has become legally recognized as equivalent to a "religion" for this purpose. In the United States, the Supreme Court recognized that Humanism is equivalent to a religion in the limited sense of authorizing Humanists to conduct ceremonies commonly carried out by officers of religious bodies. The relevant passage is in a footnote to Torcaso v. Watkins (1961). It is often alleged by fundamentalist critics of Humanism that the Supreme Court "declared Humanism to be a religion," however the Court's statement, a mere footnote at most, clearly does not in fact do so; it simply asserts an equivalency of Humanists' right to act in ways usual to a religion, such as ceremonial recognition of life's landmarks.

Renaissance humanism, and its emphasis on returning to the sources, contributed to the Protestant reformation by helping to gain what Protestants believe was a more accurate translation of Biblical texts.