 In discussing statements such as “What is known by God necessarily takes place”, Anselm of Canterbury (1033–1109) distinguished between the antecedent and consequent necessity of things which are known. The latter is the necessity of a thing’s actuality which is caused by the actuality of the thing itself. The former is the necessity by which a thing exists because of an external cause (Cur Deus homo 2.17, 125.6–126.2). Neither antecedent knowledge nor antecedent truth has a compelling effect on things. In explaining Mary’s believing the truth of a prophetic statement concerning the death of Christ, Anselm writes: