Theme 1 - A - Inductive Arguments (Cosmological)


Inductive proofs, concept of 'a posteriori'

A posteriori = A statement that is based on actual observation, evidence, experimental data or experience.

Inductive proofs = arguments constructed on evidence and/or experience. 

e.g. The Louvre is in Paris. Paris is in France. Therefore, the Louvre is in France. 

The cosmological argument states that:

  • everything that exists has a cause 
  • the universe must have a cause
  • the cause of the universe is God

Two states of being:

Potentiality = the possibility of doing or becoming something

Actuality = when potential is achieved

e.g. potential of a tree is paper, furniture, fuel etc. but it needs humans to turn the potential into the actual.

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Aquinas' First Three Ways

St Thomas Aquinas put forward five ways to prove the existence of God, the first three ways make up the cosmological argument - motion, cause, contingency.


  • observing the universe, we notice that things tend to be in a constant state of change or motion.
  • Aquinas noted that things do not do this of their own accord but instead are 'moved' or 'changed' by something else
  • He concluded that this is God, and named him the Unmoved Mover
  • Used example of wood and fire. If wood could make itself hot it would be hot to begin with.


  • Everything in nature is subject to thus law, although Aquinas said it is impossible to trace back indefinitely.
  • 'What was the first cause?' Aquinas concluded that this was God - named him the First Cause.
  • You cannot exist before you exist, you need something/someone else to bring you into existence.


  • Everything that exists has a possibility of not existing. For contingent beings to exist, there has to be a non-contingent being - a Necessary Being. Aquinas says the only possible answer is God. 
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Kalam Cosmological Argument

William Lane Craig modernised and championed this argument in 1993. Can be traced back to 9th century. 

  • Everything that begins to exist has a cause of its existence
  • The universe began to exist
  • Therefore, the universe has a cause of its existence
  • Since no scientific explanation can provide a causal account of the origin of the universe in terms of physical laws, the cause must be personal (explained in terms of a 'personal agent')

Craig developed the following defence to his second point:

  • an actual infinite cannot exist
  • a beginningless temporal series of events cannot exist
  • therefore, a beginningless temporal series of events cannot exist.

If things were infinite, we wouldn't be adding to history and adding to years, you can't add to infinite numbers.

Craig's Kalam argument is often seen as confusing, as it depends on the understanding of the concepts of infinity which are very hard to grasp. However, in its simplest form it is straightforward and appealing - it has had a significant influence in rational theistic defense against atheistic arguments.

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AO2 - whether inductive arguments are persuasive


  • the basis of the vast majority of scientifically accepted theories, these have a wide appeal in the 21st century
  • recognises that there may be more than one correct answer - the evidence used can support more than ne conclusion
  • it is an understandable evidence-based argument and has credibility
  • useful when we're unable to gather direct proof - we were not present at the time to witness the beginning of the universe, so this form of argument is flexible.


  • can be accused of having limited effectiveness as 'undeniable proofs' - this means they are weak arguments and aren't persuasive
  • it is possible to accept all premises but deny the conclusion without contradiction - people may think the universe has a cause but it is not God.
  • modern scientific age is fascinating and provides an answer to how the universe began e.g. the big bang
  • the premises, whilst supporting the conclusion, do not make it definit - for many, this means inductive arguments are not persuasive enough.
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AO2 - extent to which kalam argument is convincing


  • Craig has the advantage to Aquinas et al because he has access to contemporary scientific information about the universe: big bang theory, cosmological background information etc.
  • provides straightforward, scientifically valid evidence that the universe is finite and thus had a beginning
  • attractive argument for theists - involves modern cosmology, appears to be entirely rational.


  • potentially too much of a leap to come to the conclusion that God is the Unmoved Mover
  • you can't apply the same laws for a contingent planet to a contingent necessary being.
  • the need for Craig to prove the universe as finite is pointless.
  • not convincing to those who don't believe in God
  • self contradictory: he says infinity is impossible but later describes a personal creator as infinite.
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Quotes to learn for this section

Potentiality and Actuality:

'But nothing can be reduced from potentiality to actuality, except by something in a state of actuality' - Aquinas

Motion / change:

'It is necessary to arrive at a first mover moved by no other: and this everyone understands to be God' - Aquinas

Cause and Effect:

' Therefore it is necessary to admit a first efficient cause, to which everyone gives the name God' - Aquinas


'Therefore, if everything is possible not to be, then at one time there could have been nothing in existence'

Kalam Cosmological Argument:

'Thus, we are brought not merely to the first cause of the universe, but to its personal Creator'

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