Preface to Lyrical Ballads by William Wordsworth

Subject matter of poetry (lines 1-3, line 8)
Poetry should deal with incidents and situations from low and rustic life, transfigured by imagination and reflecting the way people think in a state of excitement.

The language of poetry (lines 3-4, line 17)
Poetry should use familiar words: a selection of language really used by men made up with simple and unelaborated expressions, and a certain colouring of imagination.

The poet's identity (lines 31-44)
The poet is a man speaking to men, but with a number of traits which set him apart from ordinary people like a more lively sensibility, a more comprehensive soul and a greater knowledge of human nature, which let him to represent ordinary things in an unusual way.

The creative act of the poet (lines 45-50)
The creative process starts from an emotion which is recollected in tranquillity. The poet is able to recreate that in his mind feeling a state of enjoyment.