Analysis of Love’s Unity

How can I tell thee when I love thee best?
In rapture or repose? how shall I say?
I only know I love thee every way,
Plumed for love's flight, or folded in love's nest.
See, what is day but night bedewed with rest?
And what the night except the tired-out day?
And 'tis love's difference, not love's decay,
If now I dawn, now fade, upon thy breast.
Self-torturing sweet! Is't not the self-same sun
Wanes in the west that flameth in the east,
His fervour nowise altered nor decreased?
So rounds my love, returning where begun,
And still beginning, never most nor least,
But fixedly various, all love's parts in one.