O! how thy worth with manners may I sing,
When thou art all the better part of me?
What can mine own praise to mine own self bring?
And what is’t but mine own when I praise thee?
Even for this, let us divided live,
And our dear love lose name of single one,
That by this separation I may give
That due to thee which thou deserv’st alone.
O absence! what a torment wouldst thou prove,
Were it not thy sour leisure gave sweet leave,
To entertain the time with thoughts of love,
Which time and thoughts so sweetly doth deceive,
And that thou teachest how to make one twain,
By praising him here who doth hence remain.
In plain English
The speaker is trapped in a problem: the young man is so central to his identity that praising the young man is just praising himself. Any worth he can claim comes from the young man anyway. So he proposes a solution—they should live apart. Separation will let him give the young man proper, undivided praise.
Absence would be torture, except that missing the young man gives him permission to spend all his time thinking about him. Those thoughts about love are so absorbing they make the time pass sweetly, almost magically turning one person into two—the young man physically absent, but constantly present in the speaker's mind and words.
