If we could could go back, and perhaps warn them, then doubtless the future from then, which is our past now, would have been different. I don't think they would have listened, nor do I think any of us, who are perhaps less set in our ways, would listen if someone from the future came to tell us something. But if they had, and things had changed, much of history would have been different, good or bad, and the what ifs are endless. Perhaps we would have more power over time, although not over men's minds if we understood it better.