In specific Shakespearean sonnets, the theme of unfaithfulness is explored as a part of human identity. It reflects a complex nature of being. This intricate development of identity as a result of unfaithfulness is a central idea in Sonnet 139. The opening lines of "O, call not me to justify the wrong/ That thy unkindness lays upon my heart;" reveals the importance of unfaithfulness in the sonnet. The idea of "wrong" and "unkindness" is directly linked to unfaithfulness, an experience that strikes at the individual. As a result, human identity embraces multiple dimensions, causing the individual to question both themselves and the people around them. Such a reality can be seen in the middle of the sonnet:
Tell me thou lovest elsewhere, but in my sight,
Dear heart, forbear to glance thine eye aside:
What need'st thou wound with cunning when thy might
Is more than my o'er-press'd defense can bide?
Unfaithfulness transforms how the individual is viewed both to themselves and to others. There is a need to be "two people." The speaker demands that the individual who practices unfaithfulness must exist as one person "in my sight" and another outside of it. This experience makes the victim of unfaithfulness offer a weakened "defense." The closing couplet helps to evoke a reality in which the individual dies from pain within, one that moves them "near slain." Sonnet 139 shows unfaithfulness as a complex condition that alters reality for the individual practicing it and the one who experiences it.
The transformative power of unfaithfulness is a theme that Shakespeare explores in Othello. It is also a force within Sonnet 42. Unfaithfulness is shown to create a bitter remnant in the heart of one who experiences it. The opening lines of the Sonnet establish a setting where the speaker sees his love in the arms of another: "That she hath thee is of my wailing chief,/A loss in love that touches me more nearly." The speaker reveals that unfaithfulness hurts on two levels. The first is when must lose someone they love to another, while the other is in witnessing the physical embodiment of that hurt when both are seen together. Unfaithfulness is a powerful element because it is shown to not merely exist in the subjective sense. It exists externally, making individual identity complex. It is for this reason that the idea "loving offenders," helps to reveal something criminal. The transformational quality of unfaithfulness is evident in the development of "excuse" or intellectual machinations that take place. The development of intricate analysis as a result of unfaithfulness shows a type of mental degradation that happens as a result of unfaithfulness. This reveals the multiple effects that unfaithfulness possesses.
Unfaithfulness is shown to be highly transformative. It is not something that enriches the human soul, but rather shows its malevolent possibilities. It makes sense that Shakespeare was able to devote an entire drama to the effect of unfaithfulness in Othello. Its presence in Sonnets 42 and 139 help to secure a passage into the darkened corners of the human psyche, where individuals are shown to be more pain- ridden and immersed in hurt. Other sonnets such as Sonnet 138 continue this exploration. In stark contrast to the vision of courtly love and a singular dimension of the love experience, Shakespeare uses unfaithfulness to intricately explore the potentially destructive aspect of love within the individual.