The Tree of Divine Doctrine from St. Thomas Aquinas' Summa Theologiae.

Response To The "Oh its just a law of thought" objection to the Ontological argument In essence, the objection says: “The ontological argument only shows that we have to think the Greatest Conceivable Being exists, but reality might be otherwise.” This response fails for at

In St. Bonaventure’s synthesis of the ontological argument, Anselm’s insight, Aristotelian logic, and Islamic metaphysics converge. Anselm provides the impossibility claim, Aristotle provides the logic of principles and reductio, and Avicenna provides the metaphysical structure

St. Bonaventure’s reformulation of the ontological argument represents a decisive moment in medieval philosophy, not because he merely repeats Anselm, but because he reconstructs Anselm’s insight using two newly available intellectual resources: Aristotelian logic and Islamic

St. Bonaventure appears to be the first thinker to reinterpret Anselm’s ontological argument through the full Aristotelian theory of first principles, integrating intellectus, reductio, per se predication, act and potency, and the structure of scientific knowledge into a unified

St. Bonaventure is the first thinker to systematically integrate the ontological argument into a fully Aristotelian noetic and metaphysical framework. Earlier Latin thinkers, including Anselm himself, supply decisive insights, but they do not possess or deploy the full

God Exists Per Se or Not at All If God exists, His existence cannot be accidental. There is no middle ground. Either existence belongs to God essentially, or God is not God. All predication falls into a strict disjunction: what is said of a thing is either essential or

St. Bonaventure’s reformulation of the ontological argument plausibly marks the high point of the classical Anselmian tradition, prior to its later transformation into explicitly modal forms by Scotus and, more fully, Leibniz. Anselm supplied the decisive insight, that God

“For completely pure being itself occurs only in full flight from non-being, just as nothingness is in full flight from being. Therefore, complete nothingness contains nothing of being or its attributes, so by contrast being itself contains no non-being, neither in act nor in

"The idea of God, or a supremely perfect being, is such that it cannot be separated from existence without contradiction." - Rene Descartes

“If there is being that exists from another, there is also being that does not exist from another, because nothing can bring itself from non-being to being.” - Saint Bonaventure, Disp. Q. Trin. I.1.,15

If nothing is necessary, nothing is impossible. If nothing is impossible, then everything is possible. A world where everything is possible leads to contradiction. Therefore, something is necessary.

“Therefore, if necessity is not in God, then there is no necessity in any being. Therefore, nothing is necessary. But if nothing is necessary, then nothing is impossible; therefore all things are possible. Therefore it is possible for one thing to both exist and not exist at the

"God is the eternal source of all being, whose existence is self-evident from His role as the uncaused cause, beyond which no greater can be conceived." - St. Bonaventure

"There are two kinds of infinite, the actually infinite and the potentially infinite. The potentially infinite God can produce, and does produce. The actually infinite God cannot produce, and does not produce." - St. Bonaventure

"God is that than which nothing greater can be conceived. But since it is true that that which cannot be thought not to be is more true than that which can be thought not to be, therefore, if God is that than which nothing greater can be conceived, God cannot be thought not to

St. Bonaventure was the first thirteenth century thinker to pay serious attention to the ontological argument; but he rightfully read the Proslogion of Anselm through Aristotelian lenses, and in doing so, is arguably the most fruitful source for a scholastic style ontological

“Therefore, if necessity is not in God, then there is no necessity in any being. Therefore, nothing is necessary. But if nothing is necessary, then nothing is impossible; therefore all things are possible. Therefore it is possible for one thing to both exist and not exist at the

In his On the Mystery of the Trinity (Paris, 1256-7) Bonaventure replied to Aquinas by saying that the that partial apprehension of the essence of God is sufficient to ground the ontological argument. This reply seems to have struck Aquinas deeply. He chose not to dispute

“The knowledge of God’s existence is naturally implanted in us.” - St. John Damascene, De Fide Orthod., c.1

“God has tempered the knowledge of himself in man in such a way that while man can never totally comprehend what God is, yet at the same time, he could never be totally ignorant of the fact that God exists.” - Hugh of Saint Victor I De Sacram., p. 3. C. 1