Lesbias rule of praise

LEsbia, whom some thought a louely creature,
Doth sometimes praise some other womans feature:
Yet this I do obserue, that none she praises,
Whom worthy fame, by beauties merits praises
But onely of their seemely parts she tels,
Whom she doth sure beleeue, her selfe excels.
So, Linus praises Churchyard in his censure,
Not Sydney, Daniel, Constable, nor Spencer.