Upload
clement-reynolds
View
228
Download
0
Tags:
Embed Size (px)
Citation preview
Parmenides of Elea
(530-450)
Claim:
Eleatics founded
1.Greek logic
2.Greek metaphysics
3.Philosophical theology
1. Greek Logic
HERACLITUS•“flux” •co-presence of opposites to assertion of contradictory statements
PARMENIDES•Principle of Non-Contradiction•Idea of Logical Deduction/Proof
ZENO•Idea of Disproof through Dialectic, Contradiciton
Heraclitus
Asserts contradictions:• Things taken together
are whole and not whole…
• We step and do not step into the same rivers, we are and we are not.
• The same thing is both living and dead, and the waking and the sleeping, and young and old…
Co-presence of opposites (CPO):
• the same thing can have both X and ~X properties (usually opposites, not just contradictories) – in reality or – as seen relative to
different things or – by different perceivers– at different times
Principle of Non-Contradiction (PNC)
Principle of Logic
Contradictory statements cannot both be true.
– “Socrates is wise” and “Socrates is not wise.”
It is not rational to ascribe opposite properties to the same object at the same time, in the same place.
PNC = ~pos (S is P & S is ~P)
Principle of Reality
Contradictory things cannot both exist. – Socrates cannot be in
Larissa and in Athens at the same time.
The world is not irrational; it is not possible that logically contradictory things exist.
~pos (S is P & ~P)
What follows from CPO?
Illogical consequences
• If A can be X and ~X, and X is Y, is A also Y?
• But if something that is X is also ~X, then if A is Y, can’t it also be ~Y?
• So we cannot really argue that if X is Y, and Y is Z, then X is Z, because it might not be.
• If A can be X and ~X, why can’t it also be ~A?
• So if COO is true, a thing might not even be itself!
Rejection of Heraclitus
• They are carried along by experience, deaf as they are blind, amazed, uncritical herds, for whom to be and not to be are judged the same and not the same, and for whom there are in all things opposites.
• That it is and cannot not be is the path of persuasion.
Greek Metaphysics
HERACLITUS•Doctrine of flux or fire real world = continuous change, becoming, no ‘being’•Doctrine of relativity no knowledge of objective reality
ELEATICS•Doctrine of ‘being’
real world based
on ‘being’ in which •Doctrine of truth based on reason knowledge of ‘what is’
Attributes of “Being”On this way there are many signs—• being ungenerated it is also
imperishable, • whole and of a single kind,
unshaken and complete. Nor was it ever, nor will it be, since it is now, all together,
• one, continuous. • For what birth will you seek for it? How and from
where did it come forth? I will not permit you to say or think that it came forth from what is not; for it is not to be said or thought that being comes to be from not-being.
• Remaining self-same in itself, being is what it is, and does not change;
• for it is contained by necessity within the bonds of limit; nor is it fitting for what is to be incomplete, for being cannot be lacking—or it would not be.
• ungenerated (imperishable /eternal)
• whole (not sum of parts)• one (not many)• known by reason, not
senses• at rest or self-same,
unchanging• necessary, not
contingent
What is being? the ‘Is’?
• Parmenides: “Is” can refer only to what is real, or what is ultimately real.
• This = – “Absolute eternal being” in contrast to the
things that ‘seem’ or ‘appear’ OR– “Enduring transient beings” which can have
opposite properties that change, e.g. color, size, etc.
Metaphysics
a. PNC applies to reality
b. Identity of objects over time (T’s ship)
– Essential properties theory (EPT)
c. Necessary vs. Contingent being
d. Metaphysical Arguments
– Cosmological Argument
– Sea Battle/Divine foreknowledge
b. Identity/’being’ of objects• Theseus, sailing ship A to
Crete, replaces plank by plank of his ship.
• Scavenger, following in ship B, picks them from the sea and replaces all the parts of his own ship, before they make land.
• Is Theseus still sailing the same ship?
• Or is Scavenger now sailing ship A?
• Parmenides: essential properties theory (EPT); identity = enduring essence
c. Contingent vs. Necessary
• Contingent truth = could not be the case, “There are tigers in India.”
• Contingent or necessary?– Natural laws ?– Empirical or historical facts?– Metaphysical truths?
• Contingent being = that which can not exist, e.g. every physical thing
• Necessary truth = must be the case, 2 + 2 = 4
• Concepts of ‘modal logic’:– necessity, possibility, actuality– 2 + 2 = 4 is T in every pos-world– There are tigers in India is ~T in
all pos-worlds [could not be T]
• Necessary being = that which cannot not exist. – God or Ideas? Souls or
Essences? Atoms?– Is this concept coherent?
d1. Cosmological Argument
• For what birth will you seek for it? How and from where did it come forth? I will not permit you to say or think that it came forth from what is not; for it is not to be said or thought that being comes to be from not-being.
1. Either (a) being (the universe?) always existed or (b) it came into being (i.e. from nothing)
2. But (b) is impossible: nothing comes into being from nothing
3. Therefore being has always been.
d2. Sea Battle
1. If it is T there will be one, it must occur.
2. If it is not T there will be one, it cannot occur.
3. Either there will be one tomorrow or not. (LEM or law of excluded middle: must be T or ~T.)
4. Therefore, the battle must or must not occur; the future, even for contingent events, is not ‘open’.
Same argument can be applied to divine foreknowledge to deny human freedom
Zeno • Parmenides: develops positive logic
to prove e.g. that there could be no beginning to “what is” & identifies key principle of logic = PNC
• Zeno: develops negative logic to disprove arguments or views of opponents by showing they are self-contradictory: his paradoxes.
The Arrow (paradoxes of motion)
• If the arrow flies toward the target, it must pass through ½ the distance, then ½ of the remaining distance, and so on.
• It will always be traversing another ½, and never reach the target.
• Likewise, Achilles will never catch up with the tortoise. He makes up ½, again ½, and so on, but never catches up.
• Conclusion: The realm of motion is incoherent.
Greek Philosophical Theology
• Initiated by Xenophanes (~540)
• Critical theology = anthropomorphism
• Positive theology = concept of God • Parmenides identifies attributes of
‘being’ (ungenerated, noncorporeal, perfect, etc.)
• Distinction of faith vs. knowledge
Critical Theology
• If oxen and horses and lions had hands, they would draw their gods to have the shape of oxen, horses, and lions.
• The Celts give the gods red hair, the Nubians make them black.
• Anthropomorphism =1. “gods” conceived in
human form
2. human passions
3. human character traits, i.e. imperfect
• Xenophanes: the Olympian gods = products of human imagination
Philosophical concept of God
• God is one, greatest among gods and men, not at all like mortals in thought or body.
• Without effort he shakes all things by the thought of his mind.
True “God” =
– One
– Radically unlike
– Acts of mind (“creation”)
– Not = Person
– Perfectly good?
Epistemology and religious belief
• No man has seen nor will anyone know the truth about the gods and the things I speak of, for even if a man said what is the case, he does not know, but only shapes a belief about it.
Later philosophical theologians: – Is there a way to know that ‘God’ (one, etc.) exists? – Might knowledge of ‘God’ be an insight of reason, not
mere belief?