I found this topic in the "similar threads" at the bottom of the page.
I'm just missing Paddawan, who has been MIA since January 2007. Where'd you go?
Quote:
Originally Posted by Paddawan  Maybe Voldemort wouldnt want the holder of such crucial information as the horcruxes to be living. Maybe voldemort wants Slughorn to join or be relieved of his life. |
He not only knew about horcruxes, he also knew that Riddle had specifically asked about them.
And, as the man said in HBP, chapter 4, page 68:
"I imagine that they would want you to turn your considerable talents to coercion, torture, and murder," said Dumbledore.
Whatever else he might be, Slughorn was intelligent enough to read the signs and to be afraid.