That is the second time you have spoken out of turn, Miss Granger,†said Snape coolly. “Five more points from Gryffindor for being an insufferable know-it-all.
When men exercise their reason coolly and freely on a variety of distinct questions, they inevitably fall into different opinions on some of them. When they are governed by a common passion, their opinions, if they are to be called, will be the same.