Compare the Italian and English sonnet form, with particular reference to "On His Blindness" and "Shall I compare".
The Italian or Petrarchan sonnet form consists of two parts: an octave (eight lines) and a sestet (six lines), between which there is a distinct change in the poet's tone/subject whereas the English or Shakespearean sonnet is composed of three quatrains and a couplet. These two forms we can see demonstrated in "On his Blindness" and "Shall I compare".
Milton ponders his purpose in life as he comes to terms with his early loss of sight in "On His Blindness". It is clear throughout the poem by the way in which he questions God and his capability without vision that he is not sure how he should continue to live a Christian life. The octave focuses around Milton's individual thoughts: "When I consider/ my days/ with me useless" whereas the language and tone in the sestet are more generalised, relating to all of humankind. The rhyme scheme reflects the shift in emphasis: abba abba/cde cde. There are ten syllables per line. When the sonnet is spoken accents fall on every second syllable; the rhythm is therefore iambic pentametre, for example "When I consider how my light is spent".
The second and third lines of the sonnet relate to the parable of the talents from the Old Testament (Matthew 25: 14-30) in which the third unprofitable servant was cast out into the darkness because he did not use his talent and fulfil his master's wishes. In Milton's case his talent is the ability to write particularly well. He expresses his frustration in not being able to use his gift to please and serve God because of his disability: "And that one talent which is death to hide lodged with me useless". Milton personifies a virtue, "Patience" in the sestet, which acts as a messenger from God in answering the question he asked in the octave. "Patience" explains if we can tolerate all God has asked us to do faithfully in life to the best of our ability without complaining our "state is kingly".