This is a short summary of Shakespeare sonnet 138. Continue reading for complete analysis and meaning in the modern text. For the complete list of 154 sonnets, check the collection of Shakespeare Sonnets with analysis. It is highly recommended to buy “The Monument” by Hank Whittemore, which is the best book on Shakespeare Sonnets.

Shakespeare Sonnet 138 (Original Text)

When my love swears that she is made of truth

I do believe her, though I know she lies,

That she might think me some untutored youth

Unlearnèd in the world’s false subtleties.

Thus vainly thinking that she thinks me young,

Although she knows my days are past the best,

Simply I credit her false speaking tongue;

On both sides thus is simple truth suppressed.

But wherefore says she not she is unjust?

And wherefore say not I that I am old?

O love’s best habit is in seeming trust,

And age in love loves not t’ have years told.

Therefore I lie with her, and she with me,

And in our faults by lies we flattered be.

–WIKI

Shakespeare Sonnet 138 Modern Text (Translation)

-via SparkNotes

Shakespeare Sonnet 138 Analysis

The poet says when his mistress is truthful to him and swears on it “When my love swears that she is made of truth” he believes her even though he knows she may be lying “I do believe her, though I know she lies,” he does this so that she will think him to be some uneducated young man “That she might think me some untutored youth” who knows nothing about the tricks of the world “Unlearnèd in the world’s false subtleties.”

He feels himself vain in thinking that his mistress regards him as a young man “Thus vainly thinking that she thinks me young,” even though she knows that he is past his prime “Although she knows my days are past the best,” he gives her credit for her lies “Simply I credit her false speaking tongue;” and in this way both he and his mistress suppresses the truth “On both sides thus is simple truth suppressed.”

He asks why she doesn’t admit she is a liar “But wherefore says she not she is unjust?” and why doesn’t she admit that he is old “And why doesn’t he too say that he is old?” because it is easy to love seemingly trustworthy people “O love’s best habit is in seeming trust,” and people who are old hate their ages discussed “And age in love loves not t’ have years told.”

This is why he sleeps with her and she with him “Therefore I lie with her, and she with me,” and in their own faults and lies, they flatter themselves “And in our faults by lies we flattered be.”