King Thamus criticizes the invention of writing, saying it will weaken people's memories and ability to think for themselves. He argues that knowledge engraved into the soul through oral teaching is better than the written word alone. Plato agrees, saying the living word of knowledge conveyed orally has a soul, while writing is just an image. McLuhan suggests that when printing was introduced, it was not clear if reading alone could effectively teach as well as the traditional methods of memorization, oral instruction, and group discussion that characterized pre-printing education. He notes new technologies impose new patterns of thinking and alter our senses of space, time, and how we learn.