"Language has two functions. One is to make communication between people possible. The other is the preservation of knowledge. Without language it would be impossible to prove any scientific truth or to learn from the experience of the past. All languages fulfill these two functions. And yet different languages have developed in such ways that each one represents the peculiar mind-set of those who speak it. A child who learns a language-that is, learns to speak at about the age of one-is already learning subconsciously the system of thinking peculiar to his language, and also its mental categories."