The Force Of Moral Arguments

Arguments on moral issues do not rely solely upon logic for their validity. There is something else present.

In normal logic, the methods of deduction of conclusions from premises are logical structures which form the "carriers" of truth.
In the usual example:

premise 1
All men are mortal.

premise 2
Socrates is a man.

 conclusion
(Therefore,) Socrates is mortal.

The sentence "Socrates is mortal" upon it own merits is not known to be true or false. The truth of "Socrates is mortal" emerges from the entire deduction above; lack one crucial element, and the mortality of Socrates becomes problematic.

However, this is not enough in moral arguments. We bring "values" to the logical table, and we usually insist that the logical deduction itself is not sufficient, nut that it must also "mesh" with our values.
If the conclusion outrages our values, we will condemn the logical conclusion, and search elsewhere.

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