T.S. Eliot once suggested that there were `three voices of poetry,' so it may be wise to begin by asking what is meant by the term `voice,' and what is meant by the term `vision"' Voice is an expression that has a variety of meanings - it could refer to the persona the poet adopts whilst writing the poem; it could refer to the author's style; the author's tone; or the characteristics of the speaker in the poem. With regards to this essay I will assume that `voice' refers to both the writer's style, and the writer's tone. Conversely, the term `vision' can be more easily defined as the author's purpose in writing the poem, and any messages or themes conveyed to the reader. The two poems that I will make reference to are `Assisi' by Norman MacCaig, and `Glasgow 5 March 1971' by Edwin...