The growth of precise terms out of original vagueness takes place normally in two directions: toward words that stand for relationships and words that stand for highly individualized traits (compare what was said about the development of meanings, p. 122); the first being associated with abstract, the second with concrete, thinking. Some Australian tribes are said to have no words for _animal_ or for _plant_, while they have specific names for every variety of plant and animal in their neighborhoods. This minuteness of vocabulary represents progress toward definiteness, but in a one-sided way. Specific properties are distinguished, but not relationships.[28] On the other hand, students of philosophy and of the general aspects of natural and social science are apt to acquire a store of terms that signify relations without balancing them up with terms that designate specific individuals and traits. The ordinary use of such terms as _causation_, _law_, _society_, _individual_, _capital_, illustrates this tendency. [28] The term _general_ is itself an ambiguous term, meaning (in its best logical sense) the related and also (in its natural usage) the indefinite, the vague. _General_, in the first sense, denotes the discrimination of a principle or generic relation; in the second sense, it denotes the absence of discrimination of specific or individual properties. [Sidenote: Words alter their meanings so as to change their logical functions] In the history of language we find both aspects of the growth of vocabulary illustrated by changes in the sense of words: some words originally wide in their application are narrowed to denote shades of meaning; others originally specific are widened to express relationships. The term _vernacular_, now meaning mother speech, has been generalized from the word _verna_, meaning a slave born in the master's household. _Publication_ has evolved its meaning of communication by means of print, through restricting an earlier meaning of any kind of communication--although the wider meaning is retained in legal procedure, as publishing a libel. The sense of the word _average_ has been generalized from a use connected with dividing loss by shipwreck proportionately among various sharers in an enterprise.[29] [29] A large amount of material illustrating the twofold change in the sense of words will be found in Jevons, _Lessons in Logic_. [Sidenote: Similar changes occur in the vocabulary of every student]