That oddly phrased sentence comes from Act IV, scene 4 of Shakespeare's "The Winter's Tale." It is only part of a sentence. In context, it reads as follows:
He says he loves my daughter:
I think so too; for never gaz'd the moon
Upon the water as he'll stand, and read,
As 'twere, my daughter's eyes: and, to be plain,
I think there is not half a kiss to choose
Who loves another best.
The shepherd is talking, saying that the young man claims he loves the shepherd's daughter, and, judging by how he stares at her, he does. However, she stares back just as hard, so there's no difference in how crazy each is about the other.