Notwithstanding it is evident that conjunctions, prepositions, and adverbs are not original and necessary parts of speech, yet as species of abbreviations, or compound terms to express assemblages of ideas, they may be considered as very useful, and as great improvements in language. Every person, even without the least knowlege of etymology, acquires a habit of annexing a certain idea, or certain number of ideas to _unless_, _lest_, _yes_, _between_, and the other particles; he uses them with precision, and makes himself understood by his hearers or readers. These words enable him to communicate his ideas with greater facility and expedition, than he could by mere names and affirmations. They have lost the distinguishing characteristics of verbs, person, time, and inflection. It is therefore convenient for grammatical purposes, to assign them distinct places and give them names, according to their particular uses. Such of these old verbs as exhibit some connection between the members of a discourse, may be properly denominated _conjunctions_. Others, that are used to show certain relations between words and are generally prefixed to them, may be well called _prepositions_. A third species, which are employed to qualify the sense of other words, may, from their position and uses in a discourse, be denominated _adverbs_. But the foregoing investigation is necessary to unfold the true principles on which language is constructed, and the philosophical enquirer is referred for a more general view of the subject, to Mr. Horne Tooke's _Diversions of Purley_. The _verb_ or _word_ is so called by way of eminence; the ancient grammarians having considered it as the principal part of speech. The _noun_ is however entitled to the precedence; it is of equal importance in language, and undoubtedly claims priority of origin. Philosophy might teach us that the _names_ of a few visible objects would be first formed by barbarous men, and afterwards the words which express the most common actions. But with respect to names of abstract ideas, as they are usually called, they not only precede the formation of the verbs which represent the action, but it often happens that the same word is used, with a prefix to denote the action of the object to which the name is given. For example, _love_ and _fear_ are the names of certain passions or affections of the mind. To express the action or exertion of these affections, we have not invented distinct terms; but custom has for this purpose prefixed the word _do_ or _to_, which, in its primitive sense, is _to act_, _move_, or _make_.[96] Thus I _do love_, or _do fear_, are merely, I _act, love_, or _act, fear_; and _to love_ and _to fear_ in the Infinitive, are _act, love_, and _act, fear_.