This phrase is usually interpreted as a metaphor where the eye is likened to a lamp.
But what if it is the other way around?
The standard reading
In the typical reading, it seems obvious that the physical eye is being likened to a lamp.
The eye shows us what is around us in the same way a lamp lights up our surroundings.
It seems straightforward. So what is the purpose of the metaphor? Is Jesus giving opthalmological advice?
The lamp of the body is the eye, if therefore the eye is clear the whole body will be full of light.
If “lamp” is the metaphorical component, then “eye” should be the literal component…but since no one thinks he was talking about literal eyes, the standard interpretation is that he’s referring either to the “mind’s eye” and hence to clear-mindedness, or “single-mindedness towards God”.
In the standard view, this passage is a metaphor within a metaphor, and it’s not entirely clear what is being said. Since the next immediate passage refers to an eye that is “evil” and a body that is full of darkness, the whole framing is reduced to “don’t be evil.”
In this reductionist ethical context the metaphor doesn’t add much value. He might as well have said “good and bad are like light and darkness, be good rather than bad, ok?” Or at best: “being good is like having good eyesight, and being bad is like having some kind of eye disease that makes you go blind.”
Rethinking the metaphor
So what if it’s the other way around instead? What if “lamp of the body” and “light” refer to something concrete and real that is then elaborated on via the metaphor of the eye?
The lamp of the body is like the eye…
If so, what is the lamp of the body?
The lamp of the body is that which “lights up” our bodies. It is what we call consciousness or the mind.
In this sense, consciousness is like an eye – the mind’s eye. We can direct it, we can focus it.
This eye can be “clear”, from the Greek haplous which literally means “without folds” and is often translated as simple or single.
And if it is single, the whole body will be full of light.
In other words, if you make your consciousness single, it will fill your whole body.
The final line warns that:
If then the light within you is darkness, how great is that darkness!
Which doesn’t make literal sense since darkness and light are opposite.
It’s another metaphor. What it refers to is that consciousness, the light within us, is not “all or nothing”.
Rather there are degrees of concentration or intensity to it.
This is something attested to universally by contemplatives and meditators from all traditions: the “normal” mind or consciousness can become imbued with a higher or more intense or more pure consciousness.
The light within us can be full of light, or it can be (comparatively) darkness.
To those who have some, more will be given, and to those who have nothing even the little that they have will be taken away.
Am I right?
This whole passage is either a moderately esoteric teaching about contemplation or an unnecessarily complicated metaphor about being a good person.
I prefer the former interpretation because it makes more sense to me. People with exposure to meditation or contemplative prayer should see what I’m getting at.
I haven’t found many others espousing the same interpretation, perhaps because esoteric or mystical perspectives on scripture tend to be either deeply private and idiosyncratic or heterodox.
But this passage is one that has always called to me, and I’m increasingly aware that my need to justify my point of view with seemingly objective or impartial reasoning doesn’t serve me.
So take it or leave it. It makes perfect sense to me.