Catechism 101: The Argument from Contingency

Catechism 101: The Argument from Contingency

Author: Dr Caitlin West August 31, 2026 Duration: 7:27

In this episode, we continue our series on St Thomas Aquinas' Five Ways by exploring his Third Way: the Argument from Contingency.

Aquinas begins with a simple but profound observation: the things we encounter in the world don't have to exist. You exist, but you could have failed to exist. The same is true of trees, mountains, planets, stars, and everything else we encounter in the created world. Philosophers describe things like these as contingent beings.


But if everything were contingent, i.e. if everything depended upon something else for its existence, then what ultimately explains why anything exists at all? Aquinas argues that contingent beings must ultimately depend upon a Necessary Being: a reality that does not receive its existence from anything else and cannot fail to exist.


In this episode, we discuss:

  • What "contingency" means in philosophy
  • The difference between contingent and necessary beings
  • Why things in the world don't contain the reason for their own existence
  • Why a collection of contingent beings cannot ultimately explain itself
  • Aquinas' argument for the existence of a Necessary Being
  • Why the Argument from Contingency does not require the universe to have a beginning in time
  • How Aquinas' Third Way differs from the Argument from Motion and the Argument from Efficient Causality
  • How Aquinas' first three Ways point towards the same ultimate reality from three different starting points


This episode is part of our series exploring St Thomas Aquinas' Five Ways and the classical philosophical arguments for the existence of God. The First Way begins with change and leads us to an Unmoved Mover. The Second begins with efficient causality and leads us to a First Efficient Cause. And the Third begins with contingent existence and leads us to a Necessary Being.


Whether you're interested in philosophy, Catholic theology, apologetics, metaphysics, or the relationship between faith and reason, I hope these episodes help make Aquinas' thought more accessible and encourage you to explore his arguments for yourself.


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For anyone curious about the foundations, traditions, and everyday implications of the Catholic faith, Crash Course Catholicism offers a thoughtful and accessible entry point. Hosted by theologian Dr Caitlin West, this podcast breaks down complex theological concepts, historical context, and Church teachings into clear, manageable conversations. Each fortnightly episode focuses on a specific topic-from the sacraments and scripture to moral philosophy and liturgical practice-providing listeners with a structured yet engaging overview. Dr West’s approach is both scholarly and welcoming, making centuries of tradition feel relevant and comprehensible. Whether you're a lifelong parishioner seeking a refresher, someone exploring spirituality, or simply a person with questions about the world's largest Christian denomination, this series is designed to inform without overwhelming. Tune in for a calm, considered journey through the pillars of Catholic thought, all delivered in short, easy-to-digest segments perfect for a daily commute or quiet moment of reflection. You can find more from Dr Caitlin West and the podcast at her website.
Author: Language: en-gb Episodes: 50

Crash Course Catholicism
Podcast Episodes
Catechism 101: The Argument from Efficient Causality [not-audio_url] [/not-audio_url]

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