Tertullian (155–220) Christian theologian
Variant translation: We conclude that God is known first through Nature, and then again, more particularly, by doctrine; by Nature in His works, and by doctrine in His revealed word. <br class="br">Book I, Chapter XVIII.—Notwithstanding Their Conceits, the God of the Marcionites Fails in the Vouchers Both of Created Evidence and of Adequate Revelation. <br class="br">This was quoted by Galileo in his defense of natural sciences. <br class="br"> Galileo Galilei: Letter to the Grand Duchess Christina of Tuscany, 1615 https://people.bu.edu/dklepper/RN242/duchess.html <br class="br"> Against Marcion https://www.newadvent.org/fathers/0312.htm <br class="br">Original: (la) Digna enim deo probabunt deum. Nos definimus deum primo natura cognoscendum, deinde doctrina recognoscendum, natura ex operibus, doctrina ex praedicationibus.