I once opened a book titled "Philosophy: Who needs it?" by Ayn Rand. It's a collection of essays and speeches by her. In it, she straightly offended Emanuel Kant saying that he singularly destroyed the world development with his philosophy.
I wondered how can an author so blatantly criticize another person or a fellow philosopher. The thought that disturbed me so much about it was that Ayn Rand may had been a very influential author/philosopher but isn't it very rude on her part to knock another philosopher down just because she didn't like his teachings???