> Inventions are just tools, and tools have no morals;
Slaves are just tools...
> I propose that the industrial age inventions simply made slavery less economical.
Exactly so. By removing the economic justification for slavery, a justification that had existed for millenia, men were freed up to see that Biblically-justified slavery was in fact morally wrong.
The rise of science, with its consequent impact on technology, changed morality.
I'm still not sure I can agree. Even at the height of slavery, there were those disagreed with it and fought against it. What was their reading of the Bible? Also, almost all cultures including non-Judeo-Christian ones practiced it, so they didn't come at it from a Biblical justification. And of course, we have the case of Nazi Germany, which enslaved people and used them as slave labor, even though they were as technologically advanced as anyone (if not moreso, depending on who you believe). And they were Christian/Lutheran. I'll have to ponder this some more to get a coherant argument one way or the other. But for now, the economic angle seems to work for me. As you said, "Slaves are just tools." You're right, and what do you do when you get a better tools to replace the older one? Chainsaw vs. axe., washing machine vs. washboard, etc.