The full poem:
My Love is like to ice, and I to fire:
How comes it then that this her cold so great
Is not dissolved through my so hot desire,
But harder grows the more I her entreat?
Or how comes it that my exceeding heat
Is not allayed by her heart-frozen cold,
But that I burn much more in boiling sweat,
And feel my flames augmented manifold?
What more miraculous thing may be told,
That fire, which all things melts, should harden ice,
And ice, which is congeal’d with senseless cold,
Should kindle fire by wonderful device?
Such is the power of love in gentle mind,
That it can alter all the course of kind.
Seemingly, the poet is saying something along the lines of: "the love of a gentle mind is capable of changing the laws of nature." What, then, is the semantic contribution of the word "kind"? The meaning of "kind" closest to the intended message I can think of is "one's inherent nature; character, natural disposition." Doesn't seem to fit exactly. Can someone clarify the meaning?