From: rescorla@rtnmr.chem.yale.edu (Eric Rescorla)
Subject: Re: A Quick Proof
Organization: Rescorla for himself.
Date: Fri, 10 Apr 1992 11:14:50 GMT

In article <1992Apr9.201142.8200@ncsu.edu> dsh@csl36h.csl.ncsu.edu (Doug Holtsinger) writes:
>In article <1992Apr9.122141.11483@cs.yale.edu> rescorla@rtnmr.chem.yale.edu (Eric Rescorla) writes:
>
>>> Premise A: All human life should have the right to determine its own
>>>            set of morals, and no human life should physically force its 
>>>            morals on others. 
>>>
>>> If you disagree with this statement, then you must agree that humans
>>> can force a woman to carry a pregnancy to term. 
>
>> Nonsense.
>> I could have premise A: No human should force a woman to carry a
>> pregnancy to term.
>
>Yes, and what does that prove? 
What it proves is that denying premise A does not mean that
humans can force a woman to carry a pregnancy to term, what else?

>> Premise A has several fatal flaws. The first obvious one is that
>> you should substitute "person" for "human life."
>
>I also could substitute "flying pigs" for "human life". What does that
>prove?
That I don't accept premise A and that therefore your whole argument
falls apart. What else?

>>> Premise B: A fetus is a human life, and therefore a fetus should have
>>>            the right to determine its own set of morals. 
>>>
>>> Follows from premise A, and the observation that a fetus is a human life. 
>
>> If you make the substitution I suggest, you need to postulate
>> that a fetus is a person. I won't do so.
 >
>Yes, but only if I make that substitution. I won't. 
Fine, then I deny your premise A. Your argument is therefore dead
in the water.

>>> Premise C: Abortion kills the fetus, and therefore abortion denies
>>>            the fetus its right to determine its own set of morals.
>>>
>>> Conclusion: If you support premise A, then it leads to the correctness
>>> of premise C, which says that abortion is wrong. If you disagree with
>>> premise A, then you agree that humans can force a woman to carry a
>>> pregnancy to term.  
>
>> Nonsense. Take a course in introductory logic.
>>
>> The thrust of your basic argument is:
>> A-->B
>> ~A-->~B.
>
>No, the last line is incorrect. I said that if you disagree with
>premise A, then you must agree that humans should be able to 
>force a woman to carry a pregnancy to term (or perhaps more correctly,
>it is not immoral to force a woman to carry to term). Hence ~A->~A .
>I did not say that if you disagree with premise A, then that implies 
>that abortion is not wrong (~B). 
Are you really as stupid as you come off.

Allow me to help you out a little bit.
Premise A:

>>> Premise A: All human life should have the right to determine its own
>>>            set of morals, and no human life should physically force its 
>>>            morals on others. 

Now, you state:

>>> If you disagree with this statement, then you must agree that humans
>>> can force a woman to carry a pregnancy to term. 

This does not logically follow.

Premise A in symbolic logic(approximately)
But first some symbol definition:
H is the class of Humans.
E is the element of symbol.
^ is and.
v is or.

(A) means for all A.
(eA) means there exists an A.

Now, premise A:
(A)(B):((A E H)^(B E H))-->(A should not physically force it's morals on B).

Now, call the act of physically forcing someone not to have an abortion
D and the class of acts which consist of physically forcing one's morals
on someone F.

Clearly (D E F)

Premise A now becomes:

(A)(B):((A E H)^(B E H)^(C E F))-->(A should not do C)

Now, represent Premise A as PA.

We can now write:
(PA)-->((A):(A E F)-->(A should not do D))

Where the second half of the implication codes as:
No human should physically force another person not to have an abortion.

Call that statement PD.


Now, "humans can force a woman to carry a pregnancy to term"
is trivially coded as ~PD where ~ is the not operator.

Now, you write:
>>> If you disagree with this statement, then you must agree that humans
>>> can force a woman to carry a pregnancy to term. 

This codes out as:
~PA-->~PD.

However, this does not follow from
PA-->PD.

Your problem is in assuming that forcing a woman to carry a baby
to term is the only member of the class F, but it's not. If it
were, your logic would hold. As it stands, however, your proof
is basically garbage.
-Ekr














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Eric Rescorla, DoD#431, Honda CM400 rider          rescorla@rtnmr.chem.yale.edu
Yale University Department of Chemistry            We hack anything.
My mind is now for rent: C/Unix,Vacuum Tech,Machining,P-Chemist. Hire me, eh?