Free inquiry must not be limited by dogma or authority

Secular humanism affirms free inquiry, that the search for knowledge and truth must not be constrained by dogma, creed, or authority, and that all beliefs and institutions should be open to questioning, evidence, and revision. Humanists hold that human understanding advances through the liberty to think, investigate, publish, and dissent, and that no doctrine should be shielded from scrutiny. Free inquiry entails freedom of thought and expression and a readiness to follow reason and evidence wherever they lead, even against established opinion.

The classic argument for free inquiry as a positive good, not merely a permitted liberty, comes from John Stuart Mill's On Liberty (1859), which held that even false or mistaken opinions should remain free to be expressed and contested, both because human fallibility means any silenced view might turn out to be true or partly true, and because even a wholly false opinion, when openly challenged, forces the true opinion to be held more vigorously than if it went unchallenged as dead dogma. Mill's argument, developed to defend general civil liberty rather than religious scepticism specifically, has become one of the most frequently cited philosophical foundations for humanist and secularist defences of free inquiry against calls to protect religious or political doctrines from criticism.

This affirmation reflects the humanist inheritance from the scientific revolution and the Enlightenment, and it underlies the movement's defence of science, education, and civil liberties. It stands against the appeal to unquestionable authority found in dogmatic systems, religious or political, and it connects to the humanist principle that belief should be proportioned to evidence. The commitment to free inquiry is central to secular humanism's self-understanding as a reason-based life-stance, and it is presented here as a value its adherents hold.

The institutional ancestry of this principle runs through nineteenth-century British secularism, especially Charles Bradlaugh, who founded the National Secular Society in 1866 and later fought a prolonged constitutional battle for the right to affirm rather than swear a religious oath on taking his seat in the House of Commons, to which he had been repeatedly elected from 1880 only to be repeatedly barred; the dispute was finally resolved by the Oaths Act 1888, which allowed a secular affirmation in place of a religious oath. Bradlaugh's case became a landmark demonstration that the abstract principle of free inquiry had concrete civic stakes, since it directly determined whether a non-religious citizen could hold public office on equal terms with religious colleagues.