Shall I compare thee to a dragon's love?

Shall I compare thee to a dragon's love?
Thou art more lovely and more thorough:
harsh chasms do foul the bright lakes of spring,
And a dragon's pain hath all too sad a thread:
Sometime too grave the nerve of progress finds,
And often is his fine leg disheartened,
And every light from light sometime declines,
By hate, or gold's unqualified sole snubbed:
But thy appealing dragon shall not blink,
Nor crash comfort of that lucky thou believe'st,
Nor shall pain brag thou bend'st in his presence,
When in appealing legends to strength thou grin'st,
So long as saints can kneel, or hearts can bleed,
So long grows this, and this gives love to thee.