AO1: Aquinas’ three ways
- Aquinas’ 1st way from motion
- By motion Aquinas means change, understood as the actualisation of a potential.
- P1. We observe motion (the actualisation of a potential).
- P2. Things cannot move themselves.
- C1. So, whatever is in motion must be moved by something already actual.
- P3. If there were no first mover, there would be no motion now.
- C2. Therefore, motion must come from a first unmoved mover (pure actuality), which we call God.
- Aquinas’ 2nd way from atemporal causation
- P1. We observe efficient causation.
- P2. Nothing can cause itself.
- P3. Causes form an ordered series from first cause to effect.
- P4. If a cause does not exist, its effect does not exist.
- C1. So, present causation must depend on a first uncaused cause, which we call God.
- Sustaining causation.
- Aquinas means a present, ongoing dependence rather than a first cause in time.
- Secondary causes depend on something more fundamental to sustain their causal power.
- For example, a hand moving a stick which moves a stone all act together, but the hand is primary.
- So, if there were no primary cause, there would be no causation or motion now.
- Aquinas’ 3rd way from contingency.
- P1. We observe contingent beings (things that can fail to exist).
- P2. If something can not exist, then at some time it does not exist.
- C1. If everything were contingent, there would have been a time when nothing existed.
- P3. If nothing existed, nothing could begin to exist.
- C2. So, there must be a necessary being, which we call God.
AO2: Hume’s critique of the causal principle
- Hume challenges the causal principle assumed by cosmological arguments.
- He argues it is not analytically true, since we can coherently conceive of an uncaused event without contradiction.
- So it cannot be established through logic.
- Attempts to justify it through experience also fail, because observing causes within the universe does not justify claims about the universe’s origin.
- The only relevant evidence would be observing the universe being created.
- So the causal principle lacks both logical and empirical support.
Counter
- Aquinas’ account of sustaining causation avoids this problem.
- We observe secondary causes which do not have independent causal power.
- Their ability to cause depends on something else sustaining them.
- This creates a hierarchy where causal power must ultimately come from a primary cause.
- A secondary cause without a sustaining cause would be incoherent, since it would have no source of causal power.
- So a causal principle based on sustaining causation can be treated as necessarily true.
Evaluation
- The idea of sustaining causation is not supported by modern science and rests on a controversial metaphysical assumption.
- It claims that causation requires ongoing support from a primary cause, rather than being explained by prior events alone.
- However, physics does not require this type of explanation.
- Theories such as Guth’s inflation model and Krauss’ account of a universe from “nothing” suggest the universe may not need a cause in the traditional sense.
- These accounts challenge the idea that causation must always apply.
- This supports Hume’s view that the universe’s origin could be a unique kind of event.
- So the causal principle is not necessary, and cosmological arguments fail to establish God as its cause.
AO2: The fallacy of composition
- Bertrand Russell argues that what is true of parts need not be true of the whole.
- Just because every human has a mother does not mean the human race has a mother.
- Likewise, even if parts of the universe have causes or are contingent, it does not follow that the universe itself has such an explanation.
- So cosmological arguments risk committing a fallacy of composition.
Counter
- Copleston replies that cosmological arguments do not infer from parts to whole.
- They begin from observed contingent things and argue that the series they form requires explanation.
- Feser notes Aquinas does not refer to the universe as a whole.
- A series of contingent beings cannot be necessary, even if infinite.
- So it still requires an external explanation.
Evaluation
- This response fails because it treats a series as if it were a concrete thing needing its own explanation.
- This is a reification fallacy.
- Hume illustrates this with a collection of particles.
- If each particle is explained, the whole collection is explained.
- There is no extra entity beyond the parts that needs further explanation.
- The same applies to a series of contingent beings.
- A series is just a mental grouping of individual events, not something over and above them.
- In an infinite series, each part can be explained by prior parts.
- So the entire series is explained without needing an external cause.
- Copleston’s argument wrongly assumes the series needs an explanation in itself, aside from its parts.
AO2: The im/possibility of an infinite regress
- Aquinas and Leibniz allow for an infinite regress, arguing that even an infinite series of causes or contingent beings still requires explanation in a primary cause or necessary being.
- Craig strengthens the argument by claiming an actual infinite is impossible.
- He uses examples like an infinite library, where half can equal the whole, creating paradoxes.
- He also argues an infinite past cannot be traversed, so the present could not have been reached.
Counter
- Hume argues there is no contradiction in an infinite regress.
- Scientific models support this possibility.
- Cyclic models suggest an eternal universe without a single infinite timeline, avoiding problems about traversing an infinite.
- Inflation theory proposes a quantum field generating universes, which may be necessary or a brute fact.
- If this exists outside time, then temporal causation and regress do not apply.
Evaluation
- Hume’s approach is more convincing because it respects the limits of philosophical reasoning.
- Craig’s arguments rely on intuitions about infinity and time that may not match physical reality.
- Scientific theories already challenge these intuitions, showing that concepts like time and space behave in unexpected ways.
- Einstein’s remark that time is “what clocks measure” reflects how unclear our understanding still is.
- If modern physics can describe models that avoid these paradoxes, then Craig’s claims lose force.
- Philosophy alone cannot decide what is possible in the physical world.
- So without empirical evidence, the claim that an infinite regress is impossible remains unproven.
AO2: The Im/possibility of a necessary being
- Hume argues that necessity only applies to logical truths, such as “1+1=2”.
- We can imagine anything existing not existing, so the idea of a necessary being is incoherent.
- There is no contradiction in denying the existence of God.
- Russell supports this by claiming necessity is a property of propositions, not things.
- So the claim that “God exists” cannot be necessary in the way cosmological arguments require.
Counter
- Copleston replies that this criticism targets the ontological argument, not cosmological arguments.
- Anselm claimed God’s non-existence is logically impossible, but cosmological arguments use a different idea.
- They claim God is metaphysically necessary as the explanation of contingent reality.
- If the world is contingent, it requires a necessary explanation.
- So God’s necessity is about explaining existence, not logical contradiction.
Evaluation
- Hume’s challenge still succeeds because it undermines the move from necessity to God.
- Even if a necessary being is coherent, it does not follow that it must be God.
- The necessary being could be the universe itself or some fundamental physical reality.
- Modern cosmology supports this possibility, with theories suggesting underlying structures like quantum fields.
- These could explain existence without appealing to a divine being.
- So Copleston’s response shifts the meaning of necessity but does not justify identifying the necessary being with God.
- Cosmological arguments therefore fail to establish a specifically theistic conclusion.
AO2: The Brute fact
- Russell argues that quantum mechanics shows some events may be uncaused.
- Copleston replies that this depends on interpretation, but Russell maintains uncaused events are scientifically conceivable.
- So, we can doubt that all reality must have a cause.
- He concludes the universe could be a brute fact, “just there, and that’s all”.
- This introduces a third option beyond Copleston’s dilemma, since reality may have no explanation at all.
Counter
- Copleston argues we cannot rule out an ultimate explanation.
- Science and philosophy both assume that events have causes or reasons.
- He interprets quantum indeterminacy as showing limits in knowledge, not reality itself.
- Even if we can only describe events probabilistically, there may still be underlying causes.
- Quantum events also depend on physical systems, so they do not show that the universe itself is uncaused.
- So, an ultimate explanation is still required.
Evaluation
- Russell’s argument is more convincing because it shows causeless events are at least possible.
- Most physicists interpret quantum uncertainty as objective, not just a limit of knowledge.
- So Copleston’s epistemological response is not well supported.
- If some events can be uncaused, it is reasonable to think the universe could also be uncaused, even if in a different way.
- This does not prove the universe is a brute fact, but it removes the necessity of an explanation.
- The principle of sufficient reason therefore becomes an assumption rather than a truth.
- So God is only one possible explanation among others, and not rationally required.