The following is a thought from my daughter Teryl Berg, in response to a post called "Great Big Mercy". 

It stands on its own as an insight into the perennial human preoccupation with light and darkness. 

Ahhh…the well-established antithesis between darkness and light.  At the risk of over-extending this metaphor, I’d like to be a darkness advocate for a minute.  (I always feel bad for the underdog.)  Alright, so I understand the generally accepted viewpoint of light as being life-giving and clarifying.  I can even relate to the religious extension of light as good and righteous.  However, after taking a few biology courses I sometimes get the feeling that darkness is being misrepresented, or at least not sufficiently appreciated.  As just one example, let’s look at the process of vision.  It seems appropriate, considering this is all a matter of perception anyways.

Vision is actually accomplished by the brain’s interpretation of sensory input from the eyes.  Our eyes are equipped with photoreceptors in the form of rods, for night vision, and cones, for vision in bright light.  The light-absorbing ability of these molecules is determined by the response of the retinal + protein configuration when exposed to light.

For example, rhodopsin (the rod configuration) undergoes a conformational change, when it absorbs light.  This change causes retinal to detach from the opsin (protein), in a process referred to as “bleaching,” rendering the photoreceptor inactive.  Bright light keeps rhodopsin bleached and unresponsive.  This is the cause of the familiar experience of temporary blindness when walking into a dark building after being outside on a sunny afternoon.  Initially your rods cannot perceive the faint light and it takes a few minutes of darkness for your bleached rods to become fully responsive again.

So why the biology lesson?  Well, I think there could be an interesting parallel between our physical vision and religious vision.  I often feel as though there is too much emphasis on the differences between dark and light (in the metaphorical sense) and not enough celebration of the delicate and necessary balance between them.  To continue the vision analogy, yes, light is essential.  Without light our photoreceptors would remain inactivated and we would be left groping in the dark.  But…paradoxically we can also be blinded by an overexposure to light, so that we lose our clarity in dimly lit situations.

Under intense light our rods become hyperpolarized and incapable of communicating with the brain. The synapse is inactive and no chemicals can be released.  Basically, darkness is required to depolarize the rod cells and reestablish that connection.  Similarly the church can become hyperpolarized, incapable of connecting to real life situations.  Those who are overexposed lose the ability to see beauty in the shadows or understand the subtlety of silhouettes.  Even colors begin to lose their distinction if the light is too intense.

I think that sometimes religion bleaches our perception to the point of sensory numbness.  We are left with a limited and washed-out vision that does not allow us to derive joy from sensory experience.  Perhaps, at times, it might be better to feel carefully in the darkness than to walk blindly in the light. 

Gwendolyn MacEwen says it best in her poem, "The Shadow-Maker."

My legs surround your black, wrestle it

As the flames of day wrestle night

And everywhere you paint the necessary shadows

On my flesh and darken the fibers of my nerve;

Without these shadows I would be

In air one wave of ruinous light

And night with many mouths would close

Around my infinite and sterile curve.