>"...enslaved more than six-hundred people over the course of his life"
Seems to me that if you do own 600 people over the course of your life you, at least implicitly, condone slavery.
If you want to write him off that quickly, feel free, but you're short sighting yourself. Finding oneself in a society with slavery, Jefferson purchased slaves from owners that abused them, and then did his best to ensure others knew the cruelty of those individuals, triggering a local society shunning of them and repercussions in their church - which at the time was very powerful. Jefferson's own handling and treatment of his slaves was extremely humane considering the status quo at that time.