 Allen, a freethinker and humanist, became an outspoken critic of organized religion and an active member of the scientific skepticism movement.He worked to promote critical thinking with such humanist and skeptical organizations as the Council for Media Integrity, a group that debunked pseudoscientific claims, and the California-based group The Skeptics Society.He wrote many pieces for their publication, "Skeptic", on such topics as the Church of Scientology, genius, and the passing of science fiction giant Isaac Asimov.