Just as one individual’s language differs from that of another individual, the language of one time differs from the same nation’s language at another time. The words of a language change or are replaced by new ones. The inflections change, are probably simplified, or as in the case of the English language, almost completely lost. The manner of forming compounds, phrases, and sentences is altered. The meaning of the words is no more fixed; many words change their original meaning entirely, even to the opposite. Changes of the former kind--changes of the sounds, their inflections, and their combinations--are brought about partly by external and fortuitous conditions, such as the Danish invasion of England or the Norman conquest, also by greater ease of pronunciation. But here the laws governing mental life are also determining factors, and in the changes of meaning every growth depends on these laws. The same forces which build up the child’s language in conformity with his experiences, thoughts, interests, and needs, bring about also the gradual changes of a nation’s language in conformity with the changing experiences, thoughts, and needs. Under special circumstances one among all the properties or features of a person or thing may occupy the mind almost exclusively, as of Julius Cæsar the despotic power which he obtained, of Captain Boycott the ban which was placed upon him. In such cases, when the name is heard and pronounced, the special feature impresses itself upon the mind. The speaker thinks of little else than this. And when the necessity arises of expressing in a word that peculiarity in another place under different surroundings, the individual name offers itself, since its original meaning has already been modified, since it has already lost most of its individual significance. The part of its meaning which is retained is now generally applied. An expansion of the special meaning has taken place.