Rumblings of ideas

I often hear myself say with annoyance that things aren't black and white - that sometimes they are grey. I'm wondering if perhaps it's not that things are grey as much as that they are both black and white at the same time. I feel more lately as if my personality, for example, is not a great blodge of grey but is in fact a complex interweaving of (or, on a bad day, epic battle between) black and white, shadow and light. I'm not sure why I feel this, or what good it does me, but it feels true. Perhaps it better honours the identity of each one, or something. (I hedge, therefore I am.)
Similarly I keep coming back to the idea of tension between two seemingly opposing, contradictory, yet co-existing ideas in the things I read and it makes sense to me that our ability and willingness to hold both black and white as true is both our biggest challenge as human beings and our fleeting glimpse of the divine, who holds all things together.
I'm reminded, as another example, of the Navajo story I wrote about here, with the 'scientific' and 'mythical' stories both considered independently true.
I think the same principles applies in the tensions we feel in life: each is independently valid and true. I read this afternoon about just such a tension in cultural psychology:

Justice is a universal of all cultures. It is a tightrope that man walks, between his desire to fulfil his wishes, and his acknowledgement of social responsibility. No animal is faced with this dilemma: an animal is either social or solitary. Man alone aspires to be both in one, a social solitary.

Jacob Bronowski The Ascent of Man (quoted in Kaufmann The Psychology of Shame)

Humans are independent and solitary: true. Humans are social creatures: true. 'Social solitary' is not grey, it is a constant tension between black and white. Richard Beck writes about another tension between love and purity, mercy and sacrifice, in his book Unclean:
Sacrifice - the purity impulse - marks off a zone of holiness, admitting the "clean" and expelling the "unclean". Mercy, by contrast, crosses those purity boundaries. Mercy blurs the distinction, bringing clean and unclean into contact. Thus the tension...And it's very hard...to both erect a boundary and dismantle that boundary at the very same time.
There is a thread of connection through these ideas and stories. I have a feeling it will turn out to be an important thread.