Vladimir Nabokov was once asked to define reality.  He said: "I can only define it as a kind of gradual accumulation of information; and of specialization.  If we take a lily, for instance, or any other kind of natural object, a lily is more real to a naturalist than it is to an ordinary person.  But it is still more real to a botanist. And yet another stage of reality is reached with that botanist who is a specialist in lilies.  You can get nearer and nearer, so to speak, to reality."  It's an arrestingly straightforward observation, that by looking at a commonplace thing through the honed sensibilities of a specialist we can apprehend a deeper reality.  So I asked my cousin, a doctor working in the Mater Hospital, to talk to me about blood. 

"I don't really see much blood," she said.  "If I do it usually means someone's made a mistake."  Ah.  Right.  "Before I learned anatomy I had this idea that the blood was sloshing about inside the body," she says, perhaps intuiting the nature of my lurid imaginings.  "But all the blood is contained in the arteries and veins.  Surgery's very bloodless.  Even if you cut into the stomach there's no blood."  Feeling a little desperate, I ask her which vein or artery a vampire would get the best juice out of.  She shakes her head at the irrelevance of it all.  "I mean, I don't know if vampires want oxygenated or deoxygenated haemoglobin, so…" She shrugs.     

 She qualified from medical school last year, and is on a convoluted path - there are HSE schemes and interviews and restricted placements involved - to becoming a general surgeon.  Her life's ambition has been unusually consistent.  When she was a child she operated on her teddy bears.  She remembers laying a patient on its back on a breadboard operating table.  She'd make an incision with an art knife, extract fluff from the incision with a tiny plastic forceps and then place the specimen in a kidney dish.  If in her considered six-year-old medical opinion the fluff was deemed healthy tissue she'd carefully replace it in the cavity and sew up the incision.  

Children usually anthropomorphise their teddies and dolls.  My cousin is so naturally unsentimental that she barely anthropomorphises human beings.  "Since I started working as a doctor I don't think I've ever had much of a sense that 'this is a person.'  Even when they're standing in front of me, talking to me, it's more of a problem solving approach. There is a human aspect to it, and it's a bit sad when they die, but I don't get into that too much."  

Over the course of four years in medical school she dissected 24 cadavers. Listening to her describing dissections I can only pity the noble souls who donated their bodies to science, stirred by the notion that in death they would provide edification to the custodians of the living. "Everybody just thinks they're disgusting.  You don't learn anything.  I would never think 'That's a body'.  None of the students appreciate the fact that someone has given up their body.  Because I think people who do it, they imagine there's a something romantic about donating your body to science, they're advancing learning, helping train people.  But anyone who's ever dissected a body would never donate."  

She invites me to consider what a cadaver looks like after a year of being systematically pulled apart by medical students.  The scooped heads, the drained, opaque eyeballs. Organs are dumped in buckets of preservative like chum.  Muscles peeled back like electrical wire, hips popped from pelvises, the ribs prised apart like a bear trap in the stranded torso.  From a pedagogical point of view, according to my cousin, "It's not even realistic.  The muscles are hard.  Everything is the same colour.  Arteries, nerves, veins, muscles, organs, skin, they're all green-grey.  To be honest, you learn more from books."

She works from seven in the morning to nine at night five days a week, and sometimes at the weekends too.  As an extremely lazy man this schedule horrifies me, as does the idea of nicking the bowel of a cadaver or worrying about contracting HIV or hepatitis-c from a patient who's a known inoculation risk.  So what is it that drives her, fascinates her?  Does helping people bring her satisfaction?  "Look, it's just like normal life," she tells me.  "Most people are annoying.  They've been waiting for two days in A&E, they hate the system and they hate doctors.  The smells I would find disgusting, and the levels of personal hygiene.  Feet are disgusting.  People can be disgusting.  But on the inside they're all the same."  I ask her a question that I hope is more profound than stupid: what's the difference between the inside of a dead body and a living body?  Her eyes light up, her hand moves through the remembered abdominal incision of a patient she is remembering, and she says: "When you put your hand in a real body it's warm, and liquid, and things are moving.  The arteries are pulsating, the bowel moves peristaltically.  You can feel this through your fingers, the life of the organs."

What she says reminds me of a phrase that's sometimes attributed to Leonardo da Vinci (though I haven't been able to verify it): movement is the essence of life.  Maybe that sounds as facile as a Zumba class tagline.  But da Vinci, that famous defiler of corpses, didn't restrict himself to the examination of dead bodies.  He dissected all manner of living animals too, removing limbs, organs, capillaries, nerves, even heads as he searched for the locus of the soul, the ghost in the machine.  He variously thought the soul might be found in the brain or in the third ventricle of the heart, but it's significant that his notes make repeated mention of the internal movement of the body.  He believed that nerve impulses were: "Spiritual movement flowing through the limbs of sentient animals that enlarges their muscles.  Whence, being enlarged, these muscles then contract and draw back their tendons…Therefore material movement arises from the spiritual."  

My cousin would have no truck with woolly phrases like 'spiritual movement'.  She's a scientist, a precision engineer of human biology.  But the contrast that made her eyes light up as between the inert grey corpse and the living, pulsating human body is what stays with me, the reminder that whatever it is - call it spiritual movement, or capital- L Life, call it the Force, if you like - whatever it is that animates the tissues of our body, shoots pulse races of oxygenated haemoglobin through our arteries, commands the liver to break down toxins that would otherwise kill us within a few days, remains an intoxicating mystery.  Even a contemporary doctor cannot tell you what this force is made of.  As Nabokov said of the quintessence of lilies: "You never get near enough, because reality is an infinite succession of steps, levels of perception, false bottoms, and hence unquenchable, unattainable."  But with your hands deep in the warm, moving liquid of life, you must feel thrillingly close.