Lecture 5 - The Argument from design
1. First Pass: Aquinas' Fifth Way
Natural bodies act for an end, including natural bodies which lack knowledge or intelligence.
Non-intelligent natural bodies which act for an end must have their action directed by a being
endowed with knowledge and intelligence.
Therefore an intelligent being exists by whom all natural things are directed to their end.
Question about the Fifth Way:
Is it really true that acting for an end or purpose requires knowledge and intelligence?
The science of self-governing machines. Greek word ‘pilot’
o Social Insects?
Are social insects a case of non-intelligent purposive behavior?
Or are social insects evidence that there must be a great designing intelligence
2. Second Pass: Paley's Watch (1743-1805)
Analogy: the watch. There must be an intelligent designer behind the watch. The parts all work
1. A watch is an elaborate mechanism whose parts serve certain ends
2.we infer that the watch was made by an intelligent watch maker
3. The universe is also an elaborate mechanism whose parts serve certain ends
4. Therefore, by analogy, we should infer that the universe was made by anintelligent universe
Three Criticisms of Paley:
a)David Hume's criticism: unintelligent design (1711-1776)
Not all things are intelligently designed. There are lots of examples of things that
could have been designed better (human eye and octopus eye)
b) argument by analogy
Because two things resemble each other in one respect, they must relate in
other respectcs as well
But argument by analogy is unreliable (=fallacious)
Leaves are complex cellulose structures.
Leaves grow on trees.
Money bills are also complex cellulose structures.
Therefore money grows on trees.
Are there any points of disanalogy between the watch and universe?
Well…the watch has an overarching purpose, namely to tell the time, but it is
not clear that the universe has an overarching purpose!
We need more content. The watch on the heath could not have come to be the complex thing that it Is
except through the agency of an intelligence watchmaker
Could the universe have come to be except through the a