+141. How languages grow.+ What we see in these cases is that, if we suppose men to have joined in cooperative effort with only the sounds used by apes and monkeys, the requirement of their interests would push them on to develop languages such as we now know. The isolating, agglutinative, incorporative, and inflectional languages can be put in a series according to the convenience and correctness of the logical processes which they embody and teach. The Semitic languages evidently teach a logic different from that of the Indo-European. It is a different way of thinking which is inculcated in each great family of languages. They represent stages in the evolution of thought or ways of thinking. The instance is one of those which best show us how folkways are built up and how they are pulled down. The agglutination of words and forms sometimes seems like a steady building process; again, the process will not go forward at all. "In the agglutinative languages speech is berry jam. In the inflectional languages each word is like a soldier in his place with his outfit."[273] The "gooing" of a baby is a case of the poetic power in its blossoming exuberance. The accidental errors of pronunciation which are due to very slight individual variations in the form of the vocal organs are cases of individual contribution to the development of language. The baby words and individual mispronunciations which are taken up by a family and its friends, but never get further, show us how dialects grow. There are changes in language which are, "in their inception, inaccuracies of speech. They attest the influence of that immense numerical majority among the speakers of English who do not take sufficient pains to speak correctly, but whose blunders become finally the norm of the language."[274] In analogy things which are alike are embraced in a single term; in metaphor two or more things which seem alike, but may not be so, are grouped together and are embraced in a single term. All these modes of change in language attest the work of individuals on language. Sometimes there is extension of influence to a group. Sometimes the influence is only temporary and is rejected again. Sometimes it falls in with a drift of taste or habit, when it is taken up and colors the pronunciation or usage of the population of a great district, and becomes fixed in the language. All this is true also on the negative side, since usage of words, accent, timbre of the voice, and pronunciation (drawling, nasal tones) expel older usages. Language therefore illustrates well all the great changes of folkways under the heads of cooperation and antagonism. We have an excellent chance to study the operation in the case of slang. A people who are prosperous and happy, optimistic and progressive, will produce much slang. It is a case of play. They amuse themselves with the language. We may think the new words and phrases vulgar and in bad taste, or senseless and ridiculous.