His first notable work was his Essay concerning the Use of Reason in Propositions the Evidence whereof depends on Human Testimony (1707), in which he rejected the distinction between "above reason" and "contrary to reason", and demanded that revelation should conform to man's natural ideas of God.
Hans vigtigste værker var Essay concerning the Use of Reason in Propositions the Evidence whereof depends on Human Testimony (1707), hvor i han afviser distinktionen mellem "over fornuften" og "imod fornuften", og krævede at åbenbaringen skulle tilpasses menneskets naturlige idéer omkring Gud.