What is 'dissociation of sensibility', which is a term coined by T. S. Eliot?

T.S. Eliot first coined the phrase in his essay, 'The
Metaphysical Poets' which was a literary criticism. The argument that he put forth was
that cultivation of emotion and thought separately as divorced from one another was a
broken way to deal with experiences that evoked both thought and
emotion.

We
may express the difference by the following theory: The poets of the seventeenth
century, the successors of the dramatists of the sixteenth, possessed a mechanism of
sensibility which could devour any kind of experience. They are simple, artificial,
difficult, or fantastic, as their predecessors were; no less nor more than Dante, Guido
Cavalcanti, Guinicelli, or Cino. In the seventeenth century a dissociation of
sensibility set in, from which we have never recovered; and this dissociation, as is
natural, was aggravated by the influence of the two most powerful poets of the century,
Milton and Dryden (Eliot, "The Metaphysical
Poets").