Aquinas Five Ways

St. Thomas Aquinas (1225-1274)
Selection from his Summa theologiae (Summary of theology), ca. 1268
Part 1, question 2, article 3 (sometimes abbreviated ST 1.2.3)
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The writing style and presentation of the medieval philosophers and theologians is quite different from how essays are written today. Thomas begins by introducing a topic (called the ‘Question’), which in this case is the existence of a God. He then examines a number of more specific issues or questions within that topic (called the ‘Articles’). Below we are looking only at the third article in this Question, the issue of whether God exists. Thomas’s method of presentation is to consider various positions or views on that issue; these are positions he will ultimately reject, and so he calls them ‘Objections’ to his thesis. (Again, the objections below are not Thomas’s position; they are positions popular or otherwise known during his day.) After the objections are presented, Thomas presents a contrary view, usually called the ‘Sed Contra’, which is the latin for what is translated below as “On the Contrary”. Again, this is not Thomas’s position; it is just a contrary position to show that debate exists on the issue at hand. Next, Thomas gives his own position on the matter, called the “Respondeo”, which is the latin for what is translated below as “I answer that”. When Thomas says “I answer that” he is giving his own considered position on the issue. Here below, he presents his view of the Five Ways to show that a God exists. Finally, Thomas offers replies to the original Objections, considering them in light of the position he endorses.

Question 2: The Existence of God
Article 3. Whether God exists?

Objection 1. It seems that God does not exist; because if one of two contraries be infinite, the other would be altogether destroyed. But the word ‘God’ means that He is infinite goodness. If, therefore, God existed, there would be...