2). Shelley's definition of poetry not only presents the central thematic concern of English Romantic Poetry –imagination– but also deals with the concept of poet, as we will observe as well in "Sonnet (Lift not the painted veil which those who live)". By saying that poetry is the expression of imagination, Shelley acknowledges the fact that poetry is the consequence of an active mental process –an adjustment of the impressions that stimulate our mind–, which implies that imagination is a creative faculty, as well as the fact that "man is an instrument over which a series of external and internal impressions are driven" (Ibid.). .
Precisely, observe that in the sestet of Shelley's sonnet, which is an inverted sonnet divided into two parts: a sestet and an octave, we are presented with a series of external impressions, whose external quality relies on the fact that they are independent to the poetic "I": the philosophical concern about reality is presented as a command rather than as a personal experience. The speaker's command establishes distance between the poetic voice and what is portrayed in the first part of the sonnet; the poetic "I" is detached from the actions that the second person, "you", is told not to do. In contrast, the octave describes a personal experience, which validates what the poetic voice has previously presented as well as highlights the importance of experience in the process of knowledge. Notice how the volta of the sonnet stresses the transition between the sestet and octave, for it signals the move from proposition to resolution and changes the focus of the sonnet: "I knew one who had lifted it" ("Sonnet" 7), but, even though in the quoted line we are presented a change of focus from a detached voice to the poetic "I", our attention is shifted again from the poetic "I" to a third person, "one".
