Introduction to Philosophy Lecture 4 Thomas Aquinas

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Introduction to PhilosophyLecture 4Thomas
Aquinas an Intro toPhilosophy of Religion

• By David Kelsey

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Aquinas

• Saint Thomas Aquinas
• Lived from 1225-1274.
• A monk whose writings have been deemed
  authoritative by the Catholic Church.
• In 1244 became a friar. Later he became a priest
  and in 1323 was made a Saint.
• Heavily influenced by the works of Aristotle.
• In his work Summa Theologica he gave 5 different
  arguments for Gods existence.
• He called these the 5 ways.

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Aquinas on Aristotle

• Aquinas on Aristotle
• Aquinas was greatly influenced by the works of
  Aristotle.
• But Aquinas thinks there is a fundamental mistake
  in Aristotles metaphysics.
• Aquinas thinks Aristotle overlooks the notion of
  existence.
• Aristotle on existence
• Form is what actualizes a potentiality, matter,
  into an actually existing thing.
• And efficient causes are what bring a particular
  substance into being.

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Aquinas on existence

• So for Aristotle, Form brings existence along
  with it. But for Aquinas, a things existence
  differs from its essence.
• For something imaginary like a phoenix, its
  essence being form and matter, it lacks
  existence.
• So existence is something added to those
  substances that do in fact exist.
• It is this new understanding of existence which
  leads Aquinas to rethink Gods existence as
  unmoved mover.
• We now turn to Aquinas famous 5 ways

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Theism

• There are 3 general argument patterns for Theism.
• Theism, Atheism Agnosticism
• We have so far seen one of these argument
  patterns the Ontological argument.
• Ontological Arguments
• Cosmological Arguments
• Teleological Arguments

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Aquinas 5 ways

• The first 4 ways
• Different versions of the Cosmological argument.
• Each way uses a different sense of the word
  cause.
• In each case Aquinas wants to show that there is
  an uncaused cause
• All Cosmological arguments have a form like this
• 1. There is something that causes everything
  else, I.e. a first cause.
• 2. Only God could be a first cause.
• 3. Thus, there is a God.
• The final way a version of the teleological
  argument.

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The first way

• The form of the first way
• 1) Things change.
• 2) Change occurs when something becomes actually
  what it was only potentially until then.
• 3) Everything that changes is made to change by
  another thing.
• 4) If change occurs, either the cause of the
  change is a first cause of change or an
  intermediate changer (from 3)
• 5) There couldnt be an open causal chain of
  intermediate changers going back forever into the
  past.
• 6) Thus, there is a first cause of change. (from
  1 5)
• 7) And this first cause is God.

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Aquinas argument for the 3rd premise

• The third premise 3) Everything that changes is
  made to change by another thing.
• A change from potentiality to actuality can only
  be brought about by something that is already
  actual.
• The ball and batter
• Nothing can be both potential and actual in the
  same respect.
• So nothing can change itself.
• Thoughts on this argument? Can you think of
  anything that could change itself?

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Aquinas argument for the 5th premise

• The 5th premise There couldnt be an open causal
  chain of intermediate changers going back forever
  into the past.
• In this case there is no first cause of change
• Open causal chain
• But then there couldnt be any intermediate
  causes either
• If there isnt a first cause then there is
  nothing to initiate the sequence. So there is no
  second cause, no third cause, etc.
• But if there werent any intermediate changers
  there would be no change at all.
• Thoughts on this argument?
• Is it possible that we have intermediate causes
  of change without a first cause?

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Evaluating the first way

• The first premise
• says simply that things change.
• Change Aquinas means the kind of change we see
  in the ball when it is hit by the bat.
• The fifth premise
• There is an unchanging changer, a first cause of
  change.
• Question how can there be a first cause of
  change assuming premise 3, everything that
  changes must be made to change by another?
• Question why suppose that there is just one
  unchanging changer?
• The conclusion
• This first cause is God
• Question why suppose this first cause is God?

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The Second Way

• The Second way
• 1) efficient causes come in series
• Something cannot be the efficient cause of itself
  for to be so it would have to preexist itself,
  which is not possible.
• And if you take away a cause you take away its
  effect
• 2) Such series of efficient causes could not go
  on to infinity
• If the series were infinite there would be no
  first cause.
• If there were no first cause there would be no
  intermediate causes...
• 3) So there must be a first efficient cause
• 4) this everyone gives the name God

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Evaluating the Second way

• Challenging the Second way
• Some things to notice
• Notice the similarity between the first and
  second ways
• The second way is focused on a specific kind of
  causation, efficient causation.
• An efficient cause causes something to come to be
• Example the hammer, the spark and the explosion
• Evaluating the premises
• Premise 1
• Questions?
• Premise 2
• Questions?
• Premise 3
• Question apply premise 1 to premise 3. How can
  there be a first cause if efficient causes must
  come in series.
• Question couldnt there be more than one first
  cause?
• The conclusion
• Questions must the first efficient cause be God?

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The Fourth Way

• The fourth way
• 1) Some things are good (noble and true).
• 2) Some things are better (or more noble or
  truer) than other things.
• 3) These better (more noble and truer) things
  have more good (are more noble and are truer) in
  accord with their distance from a maximum.
• 4) whatever is maximally good (noble and true) is
  the cause of whatever else that is good
• 5) Thus, something is maximally good and causes
  everything else that is good (from 1 4)
• 6) This maximally good thing we call GOD.

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Finishing the argument

• Something to notice
• Notice the appeal that this argument makes to the
  great chain of being
• The first 3 premises
• The fourth premise
• Question This seems to imply that the maximally
  good thing is the cause of whatever else that is
  good.
• Questions Heaviness, Heat and Good
• The conclusion

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The Fifth Way the argument from design

• The argument from design
• 1. A machine is the effect of intelligence
• For every clock
• 2. The world is like a machine
• It is an ordered whole. Newtonian mechanics
  tells us so.
• So the world is like a clock
• 3. Thus, the world is the effect of some
  intelligence
• An argument a posteriori
• it is an argument that depends upon experience
  and matters of fact
• An argument by analogy
• Worlds and machines
• A causal argument
• The first premise and conclusion

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Critiquing the Argument from design

• Critiquing the argument from design
• Note These criticisms are taken from David
  Humes Dialogues on Natural Religion
• 1. A posteriori arguments are never valid and can
  never entail their conclusions. Thus, the most
  the argument from design can give us is
  probability
• 2. Causal arguments follow this principle the
  cause must be proportioned to the effect.
• If the cause be known only by the effect, we
  never ought to ascribe to it any qualities,
  beyond what are precisely requisite to produce
  the effect. (Enquiry, 190)
• But if you look around the world it certainly
  isnt perfectly good, intelligent or wise. It
  seems to have none of the qualities we attribute
  to God and so cannot prove the existence of a
  perfect God

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The third response to the design argument

• Taking the analogy seriously The analogy is
  between machines and their designers and the
  universe and its designer.
• Many people often cooperate to make a machine ?
  Many Gods
• Wicked people can create technological marvels ?
  a wicked God
• Machines are made by mortals ? a Mortal God
• The best machines are a result of a long history
  of gradual improvements.
• But then Many worlds might have been botched and
  bungled, throughout an eternity, ere this system
  was struck out much labor lost many fruitless
  trials made and a slow but continued improvement
  carried on during infinite ages in the art of
  world-making. (Dialogues, 36)
• What Hume shows us here is that any of these is
  possible.

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The final response to thedesign argument

• The final response
• There is one respect in which the universe is
  entirely unlike machines
• The universe is entirely singular
• We can infer the cause of a machine because we
  have in the past experienced the constant
  conjunction of machines and designers.
• But if we apply this reasoning to the universe,
  we would need past experience of the making of
  worlds, such that worlds are constantly conjoined
  to designers