Aquinas's 2nd & 5th arguments for God - 1 Aquinas’s arguments for the existence of God zAquinas’s famous 5 argument appear in both the Summa Theologica

Aquinas's 2nd & 5th arguments for God - 1

Aquinas’s arguments for the existence of God

Aquinas’s famous 5 argument appear in both the Summa Theologica & the Summa Contra Gentiles

Will examine arguments 2 & 5 onlyAquinas’s approach in all of the

arguments God’s existence can be known through

God’s effects, i.e, the created world (chapter 12)



The 2nd argument1. We experience causality. 2. Nothing is the cause of itself;

causes are other than their effects.3. There cannot be an infinite

regress of caused causes.– If there were an infinite regress,

the effects we experience here & now would not exist.



The 2nd argument (cont’d)4. Therefore, there must be some

first cause and this we call “God.” Critique

Clarification: a temporal series of causes vs a dependent series. Aquinas is talking about a dependent series.



Can’t we take the observed causality in the world as a brute fact which requires no explanation?

Possible response: If we accept the Principle of Sufficient Reason, then causality must have an explanation.

•Why should we accept the P. of SR?•Because it is a necessary condition

for rationality?



Richard Swinburne (The Existence of God, 2nd ed. rev., Oxford UP, 1991) proposes redoing Aquinas’s 2nd argument

•God is necessary to account for the existence of & the sustaining of the laws of nature which in turn govern the causality we experience.



–God – laws

–causal events



The 5th argument 1. The experiential datum: things which

lack knowledge act toward ends (goals).•Nature displays goal-directedness; it

is purpose-filled. 2. Things which move toward ends must

be guided by an intelligence.•Analogy to an arrow shot by an

archer.



The 5th argument (cont’d) 3. Therefore, there must exist an

intelligent being who directs all non-cognitive natural things toward their goals. “And this we call God.”

In the 19th cenutury, William Paley (1743-1805) in his Natural Theology; or Evidences of the Existence and Attributes of the Deity (1802), redid Aquinas’s argument.



Analogy between a clock and the clock-like design and behavior of the universe as a whole and especially living things.



Critique of the design argument The challenge of Darwin’s theory to all

design arguments based on the design of living thingsThe theory of natural selection

•(1) Overproduction of pollen, seeds, eggs, & sperm; yet populations remain relatively constant.



•(2) There is a high mortality•(3) Individuals within a species are

not identical; there are some variations.

•(4) Some of these variations are inheritable.

•(5) Some individuals are better adapted than others to the conditions of life and to ecological niches.



•(6) Because of (5), there is natural selection & differential survival.

•(7) Over the long run, (6) results in the rise of divergent stocks issuing from common ancestors.

Darwin’s theory offers a natural explanation for the design of living things. Hence there is no need to appeal to God for this design.



Responses:•Can reconcile God with the natural

evolution of the design of living things by stating that God uses evolution to bring about this design.

–But note that this is not an argument for God’s existence; it is a statement of the compatibility of God the designer and evolution.



Responses (cont’d)•Swinburne: God is required to

explain the existence and sustaining of the laws governing the evolutionary process.



•Darwin’s theory is restricted to the realm of life. Some claim we need God to explain the evolution of the cosmos from the Big Bang.

–The cosmos displays remarkable fine-tuning directed toward the creation of life and mind.



– Illustrations of this fine-tuning–The expansion rate. Stephen

Hawkings: “If the rate of expansion one second after the Big Bang had been smaller by one part in a hundred thousand million million it would have recollapsed before it reached its present size”



–The formation of the elements. If the strong nuclear force were slightly weaker we would have only hydrogen in the universe. If the force were slightly stronger, all the hydrogen would have been converted to helium. In either case, stars and compounds such as water could not have formed.



– If the nuclear force had been slightly stronger, carbon would all have been converted into oxygen.

–Conclusion: This fine-tuning of the evolution of the universe can only be explained by the existence of an intelligent designer.

Documents

Aquinas's 2nd & 5th arguments for God - 1 Aquinas’s arguments for the existence of God zAquinas’s famous 5 argument appear in both the Summa Theologica