Written by Saint Thomas Aquinas (1225-1274), who would often recite this prayer before he began his studies, writing or preaching.
O infinite Creator, who in the riches of Thy wisdom didst appoint three hierarchies of Angels and didst set them in wondrous order over the highest heavens, and who didst apportion the elements of the world most wisely: do Thou, who art in truth the fountain of light and wisdom, deign to shed upon the darkness of my understanding the rays of Thine infinite brightness, and remove far from me the twofold darkness in which I was born, namely, sin and ignorance.
Do Thou, who givest speech to the tongues of little children, instruct my tongue and pour into my lips the grace of Thy benediction.
Give me keenness of apprehension, capacity for remembering, method and ease in learning, insight-in interpretation, and copious eloquence in speech.
Instruct my beginning, direct my progress, and set Thy seal upon the finished work, Thou, who art true God and true Man, who livest and reignest world without end. Amen.