Why did Samuel Johnson criticize John Donne’s comparisons as ideas “yoked by violence together”?

Samuel Johnson used the phrase "heterogeneous ideas... yoked by violence together" to describe the conceits employed by John Donne and other Metaphysical poets.12

Johnson’s criticism stemmed from the jarring nature of these metaphors, which draw ingenious, often far-fetched parallels between objects or situations that appear fundamentally dissimilar or incongruous—such as comparing parting lovers to the legs of a drawing compass. By forcing these disparate concepts into a single metaphor, Donne startled readers out of their complacency, compelling them to engage intellectually with the poem's argument rather than simply experiencing the emotion.132

While Johnson viewed this technique as a "violent" disruption of poetic harmony, modern scholars often recognize that these conceits allow Donne to transmit complex, contradictory feelings and provide brilliant, multifaceted insights into his subjects.1