There’s a sad front-page article in today’s New York Times about frontotemporal dementia, a family of degenerative brain diseases that gradually destroy not only various skills and cognitive functions, but also the essential nature of a patient’s personality. These diseases are stark reminders that what we are — that all of what we are — is a transient pattern woven in the matter of the world, a dance of atoms and energy that persists briefly, then subsides.
What is constant in all of this? What gives continuity to the “self” that connects yesterday to today to tomorrow, that makes promises today that must be kept days or months or years hence? Nothing, it seems, but the dance. The “dancers”, the individual atoms and molecules and cells and squirts of neurotransmitters — those come and go; what carries our past forward into the present and the future is nothing more than a dynamic and ephemeral configuration, like the waves of the ocean or the Great Red Spot.
These personality-annihilating illnesses are so particularly heartbreaking because they attack and destroy one of our most cherished illusions, the foundation upon which we orient ourselves in relation to others: the grounding of individual personhood in the continuity of identity. Our institutions, and indeed the social instincts from which these institutions arise and take their form, assume this continuity as their axiomatic bedrock — but as these diseases demonstrate, the ground is not so stable, and for the person whose spouse simply is no longer the person she married, the effect is surely as devastating, and as terrifying at the most primordial level, as an earthquake.