“There is nothing like it. It is stardust and the sea. The iron in our blood comes from the death of supernovas, like all iron on our planet. This bright red liquid…contains salt and water, like the sea we possibly came from.”
Hello, stranger. You and I might not know each other, but there are still a few facts I can surmise about you, the most obvious being: you have a heart and it is beating. In fact, I’d like you to place a palm over said heart and feel it. Assuming that your heart is like the majority of human hearts, the pulmonary pulsations you are now present to are just a few among 100,000 that will occur today. And while you only have a little over a gallon of blood in your system, your heart will pump the equivalent of 2,000 gallons of it through 12,000 miles worth of blood vessels in that same time—a journey four times the length of the United States.
As you read these words, some of the red blood cells in your plasma are delivering life-giving oxygen from your lungs to the rest of your tissues, while others are transporting carbon dioxide back to your lungs in order to be expelled—all part of the symphony known as your circulatory system. Meanwhile, your white blood cells may be waging a war against some unseen foreign fungi, virus, or bacteria. Those same cells may also be healing a wound you are aware of, fighting off infection while platelets plug and seal it. I know this because the same phenomena are flowing within me; I know this because blood connects us.
More than that, blood connects us with other creatures. With the exception of flatworms, nematodes, and cnidarians (jellyfish, corals, and anemones), all animals have blood. In vertebrates, it’s red because of hemoglobin. Meanwhile, spiders, crustaceans, octopuses, and squid use a pigment called hemocyanin to transport oxygen, causing their blood to be blue. Most insect blood has a yellow hue while that of ocellated icefish runs completely clear, and you can guess where the green-blooded skink gets its name. Though they may vary in appearance, all these types of blood serve a common purpose: keeping us alive.
Throughout history, cultures the world over have held that blood connects us with life itself. In her book Nine Pints, journalist Rose George chronicles not only the biology of blood, but how it has been seen as a sacred symbol of mortality—the line between life and death that all creatures are constantly towing. George likens this to the two-faced nature of the Greek gorgon Medusa, whose blood on her left side was said to be deadly and on her right, healing. This can be seen in the role that blood has played in the history of medicine; whether by bloodletting or leeching, alchemy or elemental equilibrium, blood has been seen as a means of mastering mortality.
Religions are rife with stories of sacrifice and sacrament, rooted in the belief that blood is what bonds us not only to this world, but what lies beyond it; blood connects us to the divine. This is especially evident in Christian traditions, in which red wine represents the blood of Christ, used as a consecrated emblem of communion with a god that looks human. But why should that sense of unity apply only to our species’ relationship to divinity—arguably furthering our sense of species separatism and exceptionalism—when blood is what we all share?
Dominant Western ideology has long positioned us as separate from our fellow animals and the Earth, rather than emphasizing the universality that flows through all beings, as many Indigenous cultures have always recognized. And I mean “universality” in more ways than one, for the elements found in our veins and arteries adhere us on an even more expansive scale: blood connects us to the universe. As George writes, our blood contains iron that originated in supernovas, salt and water like the sea. It even contains trace amounts of pure gold.
Maybe humanity has always had the right idea, that salvation lies somewhere in the mystery of the blood—if it can be understood as a true symbol of universality. After all, our ability to save this world might just depend on our ability to stop seeing everything through the lens of what separates us. The word “sanguine” refers to the color of blood as well as a sense of bold optimism. I feel both beating in my heart, coursing through me as I envision a future in which we remember that sacredness we share: the knowing that you and I could never be strangers.