Deism properly means belief in a God, as opposed to atheism; but the term used to express this sense is Theism (q.v.). On the other hand, Deism is generally understood to imply the denial of a revelation; and a Deist is one who holds the existence and providence of God, but grounds his belief on reason and evidence, rejecting the testimony of a revelation. The name is often used vaguely by way of reproach.
The term Deists, or Freethinkers, is usually employed to designate a series of writers who appeared in England in the 17th and 18th centuries, and sought to establish Natural Religion upon the basis of reason and free inquiry, in opposition to all positive religions, and without reference to supernatural revelation. They were critical, if not hostile, in their attitude towards Scripture, and denied miracles, the Trinity, and atonement by Christ; and they may fairly be taken as constituting one movement, though they by no means formed one school or agreed in the details of their teaching. Thus some believed and others rejected the immortality of the soul and human free-will, and they did not all teach the same doctrine as to the relation of God to the universe, some being almost pantheistic. They were not for the most part accurate scholars, and were rather acute than profound thinkers; but though their influence on English thought seemed for a time to be blotted out, they contributed largely to the progress of rationalism in Europe. The chief deists were Lord Herbert of Cherbury, called the 'Father of Deism' (died 1648), Blount, Tindal, Woolston, Toland, Lord Shaftesbury, Lord Bolingbroke, Collins, Morgan, and Chubb (died 1746). See the separate articles on these writers, also CHURCH HISTORY, RELIGION, RATIONALISM; Leland, View of the Deistical Writers (1754); Lechler, Geschichte des Englischen Deismus (1841); Hunt, Religious Thought in England (1872); Leslie Stephen, History of English Thought in the Eighteenth Century (1876).