In Johnson's preface to A Dictionary of the English Language, Johnson argues for the importance of preserving the language. Other dialects had produced their own dictionaries, such as French and Italian. Various 18th century writers were alarmed that there was no standard for the English language, because since there was no standard, it could easily become extinct. Johnson explored many points, such as how and why languages ​​change and how many words are formed. Many words derive from other languages; Johnson talks about how traders were able to communicate with those on the Mediterranean and Indian coasts. They developed a kind of jargon by mixing English with the language of traders. Johnson realized that this type of slang would not be limited to ports and might eventually become commonplace. “This will not always be confined to the stock exchange, the warehouse, or the port, but will gradually be communicated to other ranks of the people, and will eventually be incorporated into actual discourse (Johnson2751).” Johnson referred to this change as an external cause of the evolution of language, he seems to feel that it corrupts language; “Commerce, however necessary, however profitable… corrupts the language (Johnson2751).” Therefore I believe he believed that trade had a negative impact on the English language. Another form of this is when two different dialects join together to form a third dialect. Johnson didn't seem too fond of this either because he says they “...crowd his memory; and…will interject borrowed terms and exotic expressions (Johnson 2752).” I think he is saying that such dialects make no sense and only confuse the listener, because the third form is a distinct form of the other two dialects. Why not choose one and combine them to create a new one. Johnson explains that language is one of the many tests of civilization among people. As a people of class and artistic pleasure, most are well read and pursue knowledge daily. This leads to what he calls internal causes of changes in language such as that of the sciences. Many scientific terms are created to represent new ideas and discoveries. By creating a dictionary Johnson hopes to build a foundation on which to build more words and not eliminate them. I believe Johnson believes this type of change is beneficial to the English language; saying “a language is amplified” (Johnson2751).