What is "vulgar white of personal aims"? Why is it "white"?

Question

From Aurora Leigh by Elizabeth Barrett Browning:

'I have not stood long on the strand of life,
And these salt waters have had scarcely time
To creep so high up as to wet my feet.
I cannot judge these tides–I shall, perhaps.
A woman's always younger than a man
At equal years, because she is disallowed
Maturing by the outdoor sun and air,
And kept in long-clothes past the age to walk.
Ah well, I know you men judge otherwise!
You think a woman ripens as a peach,–
In the cheeks, chiefly. Pass it to me now;
I'm young in age, and younger still, I think,
As a woman. But a child may say amen
To a bishop's prayer and see the way it goes;
And I, incapable to loose the knot
Of social questions, can approve, applaud
August compassion, christian thoughts that shoot
Beyond the vulgar white of personal aims.
Accept my reverence.'

Why is it "vulgar white"? Does it refer to white paper, or white clothes?

Answer 1

Metaphor, mainly

I wasn’t able to find any exposition of the meaning of this particular passage. However, I think the meaning is fairly straightforward. Here “white” doesn’t refer to the color of “long-clothes” or anything concrete previously mentioned in the poem.

Rather, I believe “white” here is being used as a metaphor for purity. It’s not precisely the white of clothing—thought I suspect the origin of the metaphor owes something to the idea of a white robe as not having gotten dirty yet (see, e.g. the symbolism of white clothing in Revelation in the Christian Bible). The contrast here is between self-interest, which pretends to be “christian,” and is far more common (i.e. vulgar), and true “christian” values, which are more rarefied. The “thoughts” here referenced are Romney’s: he works as a social activist, which Aurora genuinely admires.

So: personal aims are “white” because they have the appearance of purity, and are “vulgar” because apparent charity born out of self-interest is far more common than genuine kindness.