(4a) If life on Mars is photosynthetic, then it will contain chloroplasts or some analogous cellular structure.
Your starting point, presupposition, will impact how you look at the conditions based on that starting point. (2a) and (1a) are standing on completely different foundations or starting points.
(2a) If God’s nature is such that He approves of rape, then rape is morally acceptable.
This assumes God exists and morality is God’s nature, you cannot seperate God from his nature. Much like from (4a) you can’t seperate the assumption that life on mars is photosynthetic.
(1a) If God does not exist, then there are no objective moral truths.
Here the assumption is God does not exist. The entire assumption of God and morality being one the same is automatically tossed.
(2a) If God’s nature is such that He approves of rape, then rape is morally acceptable.
This assumes God exists
No it doesn’t.
The Divine Character Theory can be true even if God does not exist. Some atheists actually believe that the Divine Command Theory is the correct account of moral obligation but, since they insist that there is no God, they also claim that there are no moral obligations.
In other words the believe that the claim that rape is wrong means something like,
(5a) If God commands that we should not rape, then it is wrong to rape.
But they argue that it is not wrong (in any absolute and universal sense) to rape since God does not command that we should not rape since God does not command anything since God does not exist.
I agree with these atheists that God does not exist but disagree with their account of moral obligations.
Waltercat-
I’m not sure how your latest quote goes against what I’m saying. When I state you have to assume God exists it is merely within the statement. Outside of the statement one does not have to believe God exists.
That is something that I just don’t understand. What does it mean to be within a statement?
My point is that you don’t have to presuppose that God exists in order to believe that (2a) is true. There are in fact some people who do think that (2a) is true (and non-trivially true) and yet believe that God does not exist.
My point is that you don’t have to presuppose that God exists in order to believe that (2a) is true. There are in fact some people who do think that (2a) is true (and non-trivially true) and yet believe that God does not exist.
J.L. Mackie is one of those people who takes on some versian of (2a) yet Mackie is an atheist. Mackie assumes that if objective morality exists it must be rooted in an all-powerful god. So if Mackie was given the following assertion,
6a: If an all powerful God exists objective morality exists
Mackie grants, assumes, presupposes the existence of God. Mackie for (6a) purposes grants that God exists, this of course doesn’t mean he believes in God, he grants it for the purpose of making a statment that morality could be grounded in God.
Pertaining to (2a) the “if” is God’s existence. God is assumed or granted by the definition of “if”. God is necessarilly granted within the context of (2a). Where the inexistence of God is granted in (1a). (2a) assumes God’s existence where (1a) assumes the non-existence of God. My question is why is Silenus bound to give the same answer to both of these claims where they both are bounded by diferent presuppositions/assumptions?
Mackie does not need to grant the existence of God for the purpose you suggest. In general, and once again, you do not have to grant the truth of the antecedent of a conditional in order to assert that the conditional is true.
Mackie does not need to grant the existence of God for the purpose you suggest. In general, and once again, you do not have to grant the truth of the antecedent of a conditional in order to assert that the conditional is true.
Look up ‘conditional.’
According to the definition of “if” one needs to (grant)the antecedent. What is the antedent that is granted in (2a)? God’s existence. What is the antedent that is granted in (1a)? The non-existence of God. I would be more than happy to trade “grant the truth” to simply “grant”
Conditional: Imposing, depending on, or containing a condition or conditions.
My question is why is Silenus bound to give the same answer to both of these claims (1a) and (2a) where they both are bounded by diferent assumptions, thus different conditions?
Mackie does not need to grant the existence of God for the purpose you suggest. In general, and once again, you do not have to grant the truth of the antecedent of a conditional in order to assert that the conditional is true.
Look up ‘conditional.’
According to the definition of “if” one needs to (grant)the antecedent.
That’s just not true. In order to know that
(7a) If it is raining, then the streets will be wet.
is true, I may have to grant all sorts of things. I have to grant that the streets are not covered, that water gets things wet, that when it rains water falls from the sky and lands on the ground, that the streets are on the ground, etc., etc. But one thing that I do not have to grant is that it is raining.
(7a) is true regardless of whether it is now raining, and it is true regardless of whether it has ever rained or will ever rain.
(8a) If McCain wins 270 electoral votes, then he will be the next president.
Again, in order to assert (8a) I have to presuppose that there will be an election and that the election is decided by electoral votes. But I do not have to presuppose that John McCain wins. (8a) is true whether McCain wins or loses. That is the great thing about conditionals. We don’t have to know whether their antecedents are true in order to know that they are true.
When I assert a conditional, I am claiming that it is impossible for that antecedent to be true and the consequent to be false.
