The soul or consciousness, in fact, is nothing but the unity of a sense of self over time, the bare fact that to perceive and then to articulate our perceptions something must connect from this very instant to another, and another after that.

Specifically, Kant wrote, we can picture reality as being consistent and continuous, or as being broken into discrete chunks, and we can make perfectly logical and coherent arguments supporting both conclusions even though those conclusions explicitly contradict each other. This happens because we assume something about reality that only comes into

In so doing he reveals the very insight that ignited Kant’s revolution in thought: an observation of the world can never be perfectly of the world; it always requires something else, the insertion of a minimal distance that permits it to become knowledge in the first place.

Here is how Kant put it in his Critique of Pure Reason. Whatever we think or perceive can register as a thought or perception only if it causes a change in us, a “modification of the mind.” But these changes would not register at all if we did not connect them across time, “for as contained in one moment no representation can ever be anything other

Like Kant before him, he also discovered that the conceit of slowing time down to a single frame, honing the moment of an observation to a pure present, destroys the observation itself. The closer we look, the more the present vanishes from our grasp.

without a perception, and never can observe anything but the perception.”[26] Like Knutzen staring into the heavens and mistaking the comet he sees there for the one he expected to find, when we believe that our impressions belong to a self, we falsely project an expected unity on a disjointed and random series of impressions.

Funes, Borges soon realized, lacked the basic function that permits us to think in the first place—abstraction. “Not only was it difficult for him to see that the generic symbol ‘dog’ took in all the dissimilar individuals of all shapes and sizes,” Borges recounts, “it irritated him that the ‘dog’ of three-fourteen in the afternoon, seen in

Indeed, when Kant's friend Funk died, he found himself forced to confront what is in some ways the ultimate example of the instant of change: the fact that all that we love will pass, including life itself. Even more poignantly, the very ineradicable nature of that constant, irresistible erosion of the present is what endows our life and the

To have a self, to experience anything at all, required the existence of the vast totality of space around him, of a past preceding him and a future yet to come. And yet that secret, hypothetical object, the inconceivable universe, was destined to remain hypothetical, secret, forever.