Sceptic
Charles Buck Theological Dictionary [1]
From "I consider, look about, or deliberate." properly signifies considerative and inquisitive; or one who is always weighing, reasons on one side or the other without ever deciding between them.
The word is applied to an ancient sect of philosophers founded by Pyrrho, who denied the real existence of all qualities in bodies, except those which are essential to primary atoms; and referred every thing else to the perceptions of the mind produced by external objects; in other words, to appearance and opinion. In modern times the word has been applied to Deists, or those who doubt of the truth and authenticity of the sacred Scriptures. One of the greatest sceptics in later times was Hume; he endeavoured to introduce metaphysics, history, ethics, and theology. He has been confuted, however, by the doctors, Reid, Campbell, Gregory, and Beattie.
See INFIDELITY.
Webster's Dictionary [2]
Alt. of Scepticism