Thinking About A Poem...

In the novel I am currently reading [Canada, by Richard Ford] I came across an allusion to a poem by Yeats. In the book, the narrator is thinking back upon his mother's philosophy of life, concluding that she had an ability to harmonize the dichotomous aspects of perfection and imperfection. Things being imperfect, "yet still acceptable". At one point in his youth he recalls her citing a line of poetry -- "Nothing can be sole or whole that has not been rent."
This line intrigued me, so I looked it up.

Crazy Jane Talks With The Bishop

I met the Bishop on the road
And much said he and I.
'Those breasts are flat and fallen now,
Those veins must soon be dry;
Live in a heavenly mansion,
Not in some foul sty.'

'Fair and foul are near of kin,
And fair needs foul,' I cried.
'My friends are gone, but that's a truth
Nor grave nor bed denied,
Learned in bodily lowliness
And in the heart's pride.

'A woman can be proud and stiff
When on love intent;
But Love has pitched his mansion in
The place of excrement;
For nothing can be sole or whole
That has not been rent.'
-- William Butler Yeats --

For such a short poem it's quite packed and powerful. It turns out it is the sixth in a series of seven poems Yeats wrote spotlighting this character "Crazy Jane", an old and possibly deranged woman. In this one, the Bishop admonishes her in the first stanza to finally, in her old age, renounce her former lusty ways and seek spiritual regeneration.
She replies, however, in the following two stanzas by saying [basically] that virtue and vice are not only coexistent, but actually need each other for the positive aspects of life [in this instance, sexual fulfillment vis a vis Love] to be appreciated. She denies the implication that the body is to be hated or deprived of pleasure and states that [old or not] her body remains for her the physical location of Love.
I see it as a poetic way of saying "Screw you!"
It's an ingenious capturing of so much about existence in general, I think. Nothing about it [existence] is as simple as the Bishop's statement that one is either a resident in a "heavenly mansion" OR "a foul sty." Crazy Jane points this out by suggesting her "mansion" is [anatomically] nearest the place she excretes bodily waste!
Go figure!
As for the last two lines, the initial source of my intrigue, I now paraphrase:
Wholeness necessitates an acceptance of goodness and badness / perfection and imperfection. NOTE: There is also the perhaps not so subtle suggestion that we start out torn ["rent"] and must become whole.
*****