I need to compare and contrast the themes and structures of Edmund Spenser's Amoretti Sonnet 18 to William Shakespheare's Sonnet 18.

Spenser and Shakespeare both speak of love in their
sonnets. They differ however in that Spenser's Amoretti sonnets
were written for a woman who would not return his love until much time had past while
Shakespeare wrote for loves who were won, though sometimes they had quarrels or
obstacles. Spenser's chronicle unrequited love that finally has a triumphant ending
while Shakespeare's chronicle moments in various requited (returned)
loves.

In Spenser's Amoretti Sonnet
18, the theme is the hard heart of Spenser's beloved who loves him not and will not let
his "long intreaty soften her hard hart." In Shakespeare's Sonnet 18, the theme is a
comparison. The beauty of nature that fades under "Rough winds [that] shake the ... buds
of May" and the sun's heat, that "too hot the eye of heaven shines" is compared to the
beloved's beauty that, in opposition to nature's beauty, will not fade ("But thy eternal
summer shall not fade") but instead will "in eternal lines to time" grow in
beauty.

The structure of the sonnet was originated with the
Latin poet Petrarch who structured sonnets as 14 lines comprised of an octave (8 lines)
followed by a sestet (6 lines), with no end couplet. The Petrarchan rhyme scheme is
abbaabba cdccdc, with
concatenation in each part: aa
cc. English poets varied this by changing the octave and sestet to three
quatrains (4 lines each), producing 12 lines, and adding a rhyming couplet (2 lines) for
the 13th and 14th lines. The standard rhyme scheme is abab cdcd efef
gg, with distinct rhyme separations between each quatrain and the couplet
thus eliminating concatenation. Shakespeare was not the originator of this English
sonnet structure but is certainly the poet who immortalized it; the English structure is
variously called the English sonnet or the Shakespearean
sonnet.

Spenser developed a variation on the Petrarchan
sonnet called the Spenserian sonnet. Spenser accomplished two thing with his sonnet
structure: He (1) devised an interlocking rhyme scheme through which he (2) could
develop either logical flow or opposition in the sonnet story. The Spenserian rhyme
scheme is three quatrains and a rhyming couplet in ababbcbccdcd
ee. The repetition of bb in the first
portion and cc in the second links the rhymes together: the
b rhyme carries from the first to the second quatrain
through a repetition at the 4th and 5th lines while the c
carries over from the second to the third quatrain through a repetition at the 8th and
9th lines.

This Spenserian/Petrarchan linking, or chaining,
in the rhyme is called concatenation,
built from the Latin root catena,
which means chain. Just as the rhyme
links, Spenser's stories can link (be chained together) through logical progression or
they can logically oppose each other in thought. Sonnet 18 has logical opposition: It
starts with the "rolling wheel" that can "teare" the "hardest steele," then progresses
to the failure of his tears to affect the "hard hart" of his love who "turnes hir selfe
to laughter" at his persistence. The steel is worn down by the rock in opposition to the
"steele and flint" of her heart that "doth still remayne."