Fr Joseph Pallattil

The Five Ways, Latin Quinquae Viae, in the philosophy of religion, the five arguments proposed by St Thomas Aquinas (1224/25–1274) as demonstrations of the existence of God.

The first way – The argument from the motion

The First Way focuses on motion. By “motion,” Aquinas means the three kinds of accidental change that Aristotle distinguishes: change of location (e.g., moving across the room), change in quality (e.g., heating up), and change in quantity (e.g., getting fatter). The overall insertion of the argument is that everything altered in one of these ways is changed by a little else. That something else, in changing the first thing, either is itself different or remains changeless. A series of changing changers cannot proceed infinitely. So there must be some first, unchanging being. That being we call “God.” So, Aquinas discusses first from the fact that things move in this world to the assumption that there must be a first mover which is not moved anything ‘and everyone thinks of this as God.’

The Second Way – The Argument from Causation

Although the first way concentrated on unintentional changes, the second way emphases on well-ordered series of efficient causation. The second way starts from the element that we find in the word an order of efficient causes, and the conclusion drawn is that there must be some efficient cause, which everyone calls ‘God,’ which is first in the chain of such causes.

The Third Way – The Argument from Possibility and Necessity

Aquinas has a specific understanding of possibility and necessity in mind in the Third Way, and it is not the common understanding in todays philosophical discussions. When Aquinas calls something “necessary,” in this argument, he means that it is not subject to generation or corruption. A necessary being exists, but it does not come into existence by composition, and it cannot cease existing by way of decomposition. Similarly, a possible being, in this context, exists, but it does or could have come into existence by way of composition, and it can cease to exist by way of decomposition. Therefore, Aquinas beings with the fact that we find things that have the opportunity of both being and not being, for they are things that are created and will be demolished. And, arguing that not everything will be like that, he concludes that there must exist something, called ‘God’ by everyone which is necessary of itself and does not have a cause of its necessity outside itself.

The Fourth Way – The Argument from Gradation

The fourth way starts from the fact that we find gradations in thing, for some things are more good, some less, some more true, some less and so on, and concludes that there must be something, which we called ‘God,’ which is the cause of being, and goodness, and every perfection in things.

The Fifth Way – The Argument from the Governance

Aquinas argues in the Fifth Way that if things always or for the most part act for a particular end, that is evidence of their being directed at that end by an intelligent agent. Aquinas notes that things in nature act for the sake of an end even though they lack awareness, and concludes that there must be an intelligent being, whom we call ‘God’ by whom all natural things are directed to an end. It has been argued that several of these arguments are fatally flawed by their reliance upon the antiquated physics, though other modern commentators have raised doubts about this line of criticism.