Question

In Lincoln's First Inaugural Address, he tells Southerners who have seceded the following:

I hold that in contemplation of universal law and of the Constitution the Union of these States is perpetual. Perpetuity is implied, if not expressed, in the fundamental law of all national governments. It is safe to assert that no government proper ever had a provision in its organic law for its own termination.

Which type of appeal does President Lincoln use in these lines to try to persuade Southerners?

emotional appeal
ethical appeal
logical appeal
scientific appeal
moral appeal