> Calhoun, and most everyone else in human history, lived in a different time.

Your attempt to seem wise and clever might come across a bit better if you had even the slightest aquaintence with the topic of history, about which you seem to be almost entirely ignorant. By 1837 slavery had been abolished in the countries the US would consider itself a peer of. Slavery was not some mainstream idea; it had, for decades in the civilised world, been on the run.

Appealing to the notion we are unreasonably judging the slavery advocates of the mid-19th century by their own standards shows either complete ignorance or a frankly creepy desire to propogate their philosophy.