A noun used without an article, or any other restrictive, is taken in its general sense; as, "Fruit is abundant;” “Gold is heavy;” “Man is born to trouble” Here we mean, fruit and gold in general; and all men, or mankind.

When we wish to limit the meaning of the noun to one object, but to no particular one, we employ a or an.  If I say, “Give me a pen;” “Bring me an apple;” you are at liberty to fetch any pen or any apple you please. A or an, then, is indefinite, because it leaves the meaning of the noun to which it is applied, as far as regards the person spoken to, vague, or indeterminate; that is, not definite.  But when reference is made to a particular object, we employ the, as, “Give me the pen;” “Bring me the apple, or the apple.”  When such a requisition is made, you are not at liberty to bring any pen or apple you please, but you must fetch the particular pen or apple to which you know me to refer. The is, therefore, called the definite article.

“A star appears.”  Here, the star referred to, may be known as a particular star, definite, and distinguished from all others, in the mind of the speaker; but to the hearer, it is left, among the thousands that bedeck the vault of heaven, undistinguished and indefinite.  But when the star has previously been made the subject of discourse, it becomes, in the minds of both speaker and hearer a definite object, and he says, “The star appears;” that is, that particular star about which we were discoursing.

“Solomon built a temple.”  Did he build any temple, undetermined which? No; it was a particular temple, pre-eminently distinguished from all others.  But how does it become a definite object in the mind of the hearer?  Certainly, not by the phrase, “a temple,” which indicates any temple, leaving it altogether undetermined which; but supposing the person addressed was totally unacquainted with the fact asserted, and it becomes to him, in one respect only, a definite and particular temple, by means of the associated words, “Solomon built;” that is, by the use of these words in connexion with the others, the hearer gets the idea of a temple distinguished as the one erected by Solomon.  If the speaker were addressing one whom he supposed to be unacquainted with the fact related, he might make the temple referred to a still more definite object in the mind of the hearer by a farther explanation of it; thus, “Solomon built a temple on mount Zion; and that was the temple to which the Jews resorted to worship.”

  “The lunatic, the poet, and the lover,
  Are of imagination all compact.”