Lee’s decision to fight for Virginia, and effectively the Confederacy, WAS a moral decision. Whether the south should have the right to secede by itself has moral elements, but so does why the south would risk war to secede. The south seceded primarily to protect the institution of slavery. We know this because they told us at the time that was why they were seceding. That’s extremely anti-freedom and anti-human dignity to think slavery was okay in the first place, so those are negative moral marks right there. U.S. slavery was justified on the belief that blacks were inferior, so based on racism. The south seceded because they lost a presidential election and were afraid the new president would take away their slaves. That’s not how democracy works; you don’t just get to leave when you lose an election, so that is anti-democratic. Finally, by seceding they were in open rebellion against the United States of America, meaning, they were traitors. This isn’t just an ahistorical lookback, they knew they were rebelling. They accepted certain authority of the U.S. and then rejected it, rejected it with the threat of force to defend their new authority. They took over federal facilities. Lee agrees with me on this point. A few months before the Civil War he said, “Secession is nothing but revolution” and implied that it would be “treason”. The way he used revolution seems like how we would normally say rebellion. Lee also seems to be implying that secession itself is resorting to force: “I hope therefore that all Constitutional means will be exhausted, before there is a resort to force.”
A larger quote: “The South in my opinion has been aggrieved by the acts of the North as you say. I feel the aggression, & am willing to take every proper step for redress. It is the principle I contend for, not individual or private benefit. As an American citizen I take great pride in my country, her prosperity & institutions & would defend any State if her rights were invaded. But I can anticipate no greater calamity for the country than a dissolution of the Union. It would be an accumulation of all the evils we complain of, & I am willing to sacrifice every thing but honour for its preservation. I hope therefore that all Constitutional means will be exhausted, before there is a resort to force. Secession is nothing but revolution. The framers of our Constitution never exhausted so much labour, wisdom & forbearance in its formation & surrounded it with so many guards & securities, if it was intended to be broken by every member of the confederacy at will. It was intended for pepetual [sic] union, so expressed in the preamble,4 & for the establishment of a government, not a compact, which can only be dissolved by revolution or the consent of all the people in convention assembled. It is idle to talk of secession. Anarchy would have been established & not a government, by Washington, Hamilton, Jefferson, Madison & the other patriots of the Revolution. In 1808 when the New England States resisted Mr Jeffersons Imbargo law & the Hartford Convention assembled secession was termed treason by Virga statesmen. What can it be now?” ~ Lee
The south didn’t simply secede on the principle of states rights. They weren’t thinking that we must stand up for states rights for the principle of states rights in and of itself. They weren’t inspired by the value of states rights. They wanted to maintain the institution of slavery. That is why the south risked war. That is why they seceded. Lee knew that. Lee knew that the south didn’t like the outcome of a presidential election, didn’t want Lincoln to take their slaves away, justified slavery based on racism, and were rebelling against the United States by non-Constitutional means. Despite knowing this, he chose loyalty to his beloved Virginia above all else. That is not simply a civics question, but a deeply moral choice.
I don’t condemn Lee for his choice. I think we can clearly say that it was the morally wrong choice, but also understand him in his time and his culture and have sympathy with why he made that decision. And understand that he was in many ways a good man despite certain mistakes and blind spots.