Language, colour, form, and religious and civil habits of action, are all the instruments and materials of poetry; they may be called poetry by that figure of speech which considers the effect as a synonym of the cause.  But poetry in a more restricted sense expresses those arrangements of language, and especially metrical language, which are created by that imperial faculty; whose throne is curtained within the invisible nature of man.  And this springs from the nature itself of language, which is a more direct representation of the actions and passions of our internal being, and is susceptible of more various and delicate combinations, than colour, form, or motion, and is more plastic and obedient to the control of that faculty of which it is the creation.  For language is arbitrarily produced by the imagination and has relation to thoughts alone; but all other materials, instruments and conditions of art, have relations among each other, which limit and interpose between conception and expression The former is as a mirror which reflects, the latter as a cloud which enfeebles, the light of which both are mediums of communication.  Hence the fame of sculptors, painters, and musicians, although the intrinsic powers of the great masters of these arts may yield in no degree to that of those who have employed language as the hieroglyphic of their thoughts, has never equalled that of poets in the restricted sense of the term, as two performers of equal skill will produce unequal effects from a guitar and a harp.  The fame of legislators and founders of religions, so long as their institutions last, alone seems to exceed that of poets in the restricted sense; but it can scarcely be a question, whether, if we deduct the celebrity which their flattery of the gross opinions of the vulgar usually conciliates, together with that which belonged to them in their higher character of poets, any excess will remain.

We have thus circumscribed the word poetry within the limits of that art which is the most familiar and the most perfect expression of the faculty itself.  It is necessary, however, to make the circle still narrower, and to determine the distinction between measured and unmeasured language; for the popular division into prose and verse is inadmissible in accurate philosophy.

Sounds as well as thoughts have relation both between each other and towards that which they represent, and a perception of the order of those relations has always been found connected with a perception of the order of the relations of thoughts.  Hence the language of poets has ever affected a certain uniform and harmonious recurrence of sound, without which it were not poetry, and which is scarcely less indispensable to the communication of its influence, than the words themselves, without reference to that peculiar order.  Hence the vanity of translation; it were as wise to cast a violet into a crucible that you might discover the formal principle of its colour and odour, as seek to transfuse from one language into another the creations of a poet.  The plant must spring again from its seed, or it will bear no flower—­and this is the burthen of the curse of Babel.