Before the mind’s eye, whether in sleep or waking, came images that one was to discover presently in some book one had never read, and after looking in vain for explanation to the current theory of forgotten personal memory, I came to believe in a great memory passing on from generation to generation. … Our daily thought was certainly but the line of foam at the shallow edge of a vast luminous sea.

—W. B. Yeats, Mythologies, 346 (1917)

This beautiful thinking came to me from Ben Novak, who read it here, where there is a further meditation on its meaning:

Yeats called this ‘great memory’ anima mundi; but these images are phenomena of the human world, the world of the human imagination, passing on from generation to generation of humans. When they are meaningful, they are iconic signs occurring in various contexts and occupying human meaning spaces. Who knows what they would mean to other imaginations, to other animals? Yet we can’t help believing that they arise from much deeper in the bottomless lake of consciousness than the ephemeral chatter of ‘our daily thought’ – perhaps even from the deeper-than-human.

This reminds me of something I read not long ago: the suspicion that our genetics may be passing along, in some way, bits of the actual memory of our genetic ancestors.