I am not sure that he was cold blooded. He was an expert on sheep breeds, and as a consultant, traveled a lot. He got to see conditions on many farms in many parts of the country. That would have given him reason to have ‘hot blood’.
The Southeron’s raided Lawrence, and Brown intercepted a raiding party effectively. Given that the south was murdering to spread slavery, he thought that setting up a defensive/offensive strategy in the Old Dominion would, perhaps without much bloodshed, end the institution. We were not to be so blessed.
Fredrick Douglass disagreed with him, as did most other abolitionists. That is why Brown’s expedition to Harper’s Ferry was so small. Odd that the dander of the slavers was so raised when most abolitionists didn’t support Brown. Must be the memories of Nat Turner.
Osawattamie was not an interception of a raiding party.
It was a cold-blooded massacre of innocent people.
Lawrence was in retaliation for the depredations of the Jayhawkers.
John Brown wanted another slave uprising. He was justly hanged.