Sometimes I dream of a great tree. I dream of it at night but more and more during the day as well. I feel it may come to me in many guises, in other forms. In the dream it is a monarch of a tree, as if the land of trees had elected it unanimously to represent their kingdom. The trunk is so wide that it loses curvature up close, and only by stepping back dozens of paces does it finally resolve itself into a three-dimensional shape. A sequoia. Larger than any I saw in California. A great towering and branching sequoia, all alone in a great field. It is always night where the tree is. Thousands of years old, it spans the history of human civilization. Its mammoth trunk brachiates into knotty giant offshoots that run almost perpendicular to the ground, and this epigeous brachiation continues on and on, tufts of bushy dark green sprouting off, making the tree even greater in reach than it is tall. The body of it is huge even at the higher areas, the diameter of the branches large enough for a man to easily walk on, except at the very top where hundreds of feet up one has to climb carefully on the swaying branches, hoping they hold your weight, such that only the very tips of your fingers ever clear the tree and end up in the cold, infinitely fresh air. Above it swirl the richest stars you will ever see. The backbone of the Milky Way is a bright speckled bridge across the sky. One can almost see the hazy spun disk of light that is the Andromeda galaxy engaged in its four-billion-year collision course with us. The twinkles of stars are like pinholes poked in the canvas of the sky, and wherever you turn your head, to whichever direction you fix your gaze there is cosmic scenery, for the tree stands in some relation to the stars, but it is the kind of unspeakable relation that only deeply old and deeply natural things can possibly share with one another. Down at the base of the tree steps have been carved into its side, wrapping around, and there is occasional evidence of human engineering and controlled growth. And out along the thick roads of the branches, all over that expansive arboreal kingdom, are shadowed figures, sometimes moving about in small, lit areas, outlines of human forms. This is Yggdrasil. The world tree. The tree of knowledge. And on it wander those who have advanced it, natural philosophers all. There is an organization to it—older discoveries and more fundamental theories are medial to the trunk, and then the farther along a branch one goes, the more modern. This is often reflected in the means of illumination: the light at the base is from torches or fires, and then higher still candles, then lanterns burning whale oil, then hanging light bulbs and computer screens near the outer layers. I am simultaneously on the tree and looking at myself on the tree from the ground. How can both be true at the same time? Walking out along the branches faces come out at you in the darkness suddenly, and each is rough with a wild wisdom. Exploring at the base I find Plato, twenty-eight, only a year older than I, all in black and looking outward into the night. From his solemn stare I surmise he must be gazing out at the tombstone of his mentor Socrates. Just a bit farther down I see Aristotle with his notes and specimen samples but I don’t approach. My destination is the outer branches and although I am torn with curiosity I push on, finding footholds carefully in some places, while in others I can proceed at a steady stride. The order of the tree is not always what I expect, although in general it obeys the hierarchy of the sciences: philosophy and mathematics at its base and then physics, chemistry, biology, psychology, economics, and sociology (these branches seem flimsy and enervated at the very top). I linger over Leibniz and race past Rutherford, then have to backtrack until I find Galen standing next to a cot where a diseased man clutches something—a cross? Galen is whispering soothingly in ancient Latin. After a few more figures I come to William Harvey, who stands next to the ghoulish vivisected body of a horse strung up between two thin offshoots of the tree that form an X, a Roman crucifixion, with the valved and chambered great equine heart struggling to contract in the dim light of candles, and he says to himself— “It’s a pump that circulates. A pump! And the body is a complete circuit.” Higher up, William James is here. He’s alone and well-dressed but in near-total darkness along an empty section of a branch of the tree. Quiet and kneeling he does not turn to me as I pass but I hear a continuous murmur. I think he is praying. Tracking sideways a bit, finding a connecting branch, I come upon Francis Crick. The confident thirty-five-year-old is seated at a small table with a half-full beer and is sketching on a bar napkin under a single illuminating bare bulb and I can make out the twist of a helix in bleeding pen. And near the end of the branch Antonio Moretti is on the tree. Perhaps him being here is just a personal affectation of mine, or maybe the tree has some sort of a fractal structure, whereon, zooming in on a branch, more branches are revealed, endless, and in the end everyone is somewhere on the tree. Regardless, he is here, looking just as I knew him. He has in his hands a chewed pencil and sheets of paper which contain causal diagrams and logical mechanisms and information theory terminology. He is impeccably dressed in a sports jacket and bolo tie. He turns from me as I approach and will not look upon me. At times I switch temporal perspectives, flipping back to being on the ground gazing up at the tree’s enormous arboreal outline before I have climbed it—it is then that I am enraged by the tree, I attack its base, I scream at it and tear at the impenetrable armor of its trunk. I think of ways of chopping it down, each more outlandish than the next. But I know that this is mere release, catharsis, as I could never truly injure it. I have neither the tools nor the will. But I do prostrate myself on my knees to beg, to asking pleadingly—where on the tree? Where on the tree would a theory of consciousness be placed? On what far and tangential branch? On physiology as it turns to neurology? Past computer science toward the arcane side of information theory? Off of mathematics and physics? From where would it grow? An extension of analytic philosophy? What of the far tuft that is complexity science and the language of state-spaces? The only question I ever ask it as I beg or rage—where on the tree? Where on the tree? And what figure will be paused there frozen in the discovery of it? A face illuminated by the revelation, yes, but the eyes clouded cataract white, struck blind by the Damascene light. For no revelation is without cost . . .