I find myself reflecting on mortality these days—wondering as we all do whether the elusive entity that we call “self” survives the death of the body. One of the most tantalizing suggestions I’ve heard comes from psychologist and neuroscientist Stephen Kosslyn. Back in 2005, he was asked this question:

“What do you believe is true even though you cannot prove it?”

His answer really intrigued me:

Your mind may arise not simply from your own brain, but in part from the brains of other people.

Kosslyn’s explanation is simple and utterly non-mystical. To sum it up crudely, your mind is not entirely self-contained within your skull. In order to perform certain complicated mental tasks, you must extend the limits of your physical brain with “prosthetic systems”—for example, an electronic calculator to multiply 756 by 312, which is rather difficult to do in your head.

As it happens, people perform this very same function for one another. Human beings set up what Kosslyn calls “Social Prosthetic Systems” (SPSs) in which people share their brainpower to solve countless challenges. A marriage might be the most sophisticated SPS of all—a relationship in which two people are constantly (and quite literally) sharing brains. As Kosslyn puts it,

parts of other people’s brains come to serve as extensions of your own brain. And if the mind is “what the brain does,” then your mind in fact arises from the activity of not only your own brain, but those of your SPSs.

Kosslyn isn’t blind to the enormous implications of this idea:

In fact, one could even argue that when your body dies, part of your mind may survive.

Cognitive scientist Douglas Hofstadter has expressed much the same notion:

You can imagine a soul as being a detailed, elaborate pattern that exists very clearly in one brain. When a person dies, the original is no longer around. But there are other versions of it in other people’s brains. It’s a less detailed copy, it’s coarse-grained.

This concept of life after death might strike you as painfully prosaic. It’s certainly a far cry from Wordsworth’s belief in a soul that not only survives the death of the body, but has existed always:

Our birth is but a sleep and a forgetting:
The Soul that rises with us, our life’s Star,
Hath had elsewhere its setting,
And cometh from afar:
Not in entire forgetfulness,
And not in utter nakedness,
But trailing clouds of glory do we come
From God, who is our home …

I’m open to such sentiments, which harmonize well with mainstream religious and mystical beliefs. But the simplicity and earthiness of Kosslyn’s idea holds a certain beauty for me. And I don’t seem to be alone in feeling this way.

After Hofstadter’s wife, Carol, died in 1993 at the age of 42, he experienced an epiphany while looking at her picture one day. In his book I Am A Strange Loop, Hofstadter describes how he was overcome with the realization that Carol’s soul and his own had fused “into one higher-level entity” shaped out of shared hopes and dreams for their children. Their hopes

were not separate or distinct hopes but were just one hope, one clear thing that defined us both, that wielded us into a unit, the kind of unit I had but dimly imagined before being married and having children. I realized that though Carol had died, that core piece of her had not died at all, but that it had lived on very determinedly in my brain.

That sounds to me like a kind of immortality well worth hoping for.