The manner in which human anatomy had been taught for the past 1400 years had been dominated by the medical doctrines written by Claudius Galen - surgeon of the gladiators of Pergamon and physician to Marcus Aurelius.
His teachings were presented as irrefutable truths which also explains the scarcity of scientific discoveries as they related to the human tissues after Galen's death in 210 A.D
Up until the middle of the 16th century, whenever cadavers were presented and dissected in the candle-lit classrooms of the time, it was little more than an added dramatic effect to when Galen's archaic texts were read out loud - expected to be both trusted and memorized.
In fact, dissections were most commonly performed by local barber-surgeons. The professors didn't actually touch the corpses. They were too busy repeating what Galen already had said, and pointing out to the students what they should be seeing.
And so, despite the fact that skin was peeled, flesh was torn from bone and the framework of the human body was exposed for all to see, neither professors or students dared check to see if Galen was actually right. To do so, to question the veritable prince of medicine, would be sacriligeous.
That is, until there was Andreas Vesalius.
In 1537, at the tender age of 23, Vesalius graduated from the University of Paris, where he himself studied Galen's time-honored medical texts. The day after his graduation he was offered a lectureship.
It was during this time Vesalius, who thought it silly that the professors didn't personally dissect the corpses, decided to take a closer look. He would even go so far as to involve the students, encouraging them to poke and prod the corpses alongside with him.
The young, Flemish man was taken aback by what he discovered.
The human jaw consisted of one bone, not two, like Galen had professed.
The breast bone was made up of 3 parts, not 7.
The liver had five lobes, not two.
Men and women had the same number of ribs.
If Galen was mistaken about such obvious aspects of the human body, what more could he have been wrong about?
Fueled by relentless curiosity, Vesalius would continue to uncover more than 200 misconceptions about anatomy. As he pointed these out, he would also announce that Galen's shortcomings were not due to a lack of skill or intellectual prowess, but rather an absence of resources. After all, in ancient Rome, carving up human cadavers was illegal. Claudius Galen had simply opted for the next best thing, and had made his conlusions by inspecting monkeys, pigs, oxen and dogs instead.
Vesalius's announcement was celebrated by many students and frowned upon by several colleagues. Many of those who considered themselves educated were of the opinion that their job was not to uncover knowledge, but rather to memorize and communicate the teachings of the one who had already mastered anatomy; Claudius Galen.
In 1543, Vesalius finished the book that would allow anatomy to take its next and biggest step.
De Humani Corporis Fabrica, the seven-book compendium that is arguably the most influential and important medical text ever written, was published.
This masterpiece set the standard for how anatomy not only should be taught, but also how it should be learned.
What we can learn from Vesalius
De Humani Corporis Fabrica is a work of art - not just because of the immense amount of research that went into the book, but also because of how the information was presented.
Vesalius was of the opinion that anatomy shouldn't be a simple inspection of a corpse, but rather a study on life. When he commissioned illustrations for the book, he requested that the bodies were to display emotions and to be presented in beautiful, realistic landscapes.
This was to remind the readers that anatomy can be studied on paper, but can only be understood by examining life.
This lesson still applies. If you're studying anatomy, chances are that you're doing so in order to deal with something that is still living and breathing. In that case you would do well to remind yourself, like Vesalius reminded his peers, that there's more to humans than the individual parts we consist of.
Respect - Don't Trust
Vesalius had an immense respect for Claudius Galen, as well as his other teachers. However, as he himself stated:
At this point, however, I have no intention whatever of criticizing the false teachings of Galen, who is easily first among the professors of dissection, for I certainly do not wish to start off by gaining a reputation for impiety toward him, the author of all good things, or by seeming insubordinate to his authority. For I am well aware how upset the practitioners invariably become nowadays, when they discover in the course of a single dissection that Galen has departed on two hundred or more occasions from the true description of the harmony, function, and action of the human parts… Yet even they, drawn by their love of truth, are gradually calming down and placing more faith in their own not ineffective eyes and reason than in Galen’s writings.
Vesalius understood that his respect for Galen was due to their common passion for the profession of healing. As such, to trust Galen blindly would also be to turn a blind eye to the craft.
In my personal experience, the teachers I've found to have the greatest impact on my life are also the ones who've taught me enough to let me question them.
Trust should of course be given when dealing with people and their experiences, but to do so at the cost of the respect necessary for the progression of our shared love - whether that be arts, crafts, relationships or science - might be to our detriment.
A Monkey is not a Man. A Man is not You.
Galen dissected several Barbary Macaques. This was the closest he could get to dissecting a human being without violating laws.
Vesalius's contributions to anatomy were due to his personal, hands-on investigations of the human cadavers he was able to get his hands on - these were usually recently executed criminals of some sort.
Nowadays, anatomy has come a long way. Hundreds of thousands of autopsies and dissections have allowed us to get an even more comprehensive idea of what a human body is.
However, in present times it is important to remind ourselves that what we see in the anatomy books is the average body.
The average body is a social construct - it doesn't actually exist. If we were worked on the assumption that what we see in the books is normal, then we would all be freaks of nature.
Just averting our eyes from the books and looking at the vast differences of people's external appearance should give us a clue about how different we can look on the inside.
Extra bones, nerves and muscles. Assymetry. Different placement of organs, as well as "abnormal" origins, insertions and shapes of muscles. These are more commonly found than whatever is presented as normal.
In fact, one might say that being normal is less normal than being abnormal.
Aristotle and many others attribute more teeth to men than to women; it is no harder for anyone to test this than it is for me to say it is false, since no one is prevented from counting teeth - Andreas Vesalius
We have so much more information available to us now than Vesalius ever did.
Nevertheless, by being willing to challenge what was taught, making sure that his eyes were as clear as his mind was free from preconceptions, he was able to revolutionize the field of anatomy.
This is perhaps the most important lesson Vesalius taught:
We shouldn't turn our backs to the power of observation simply because we believe to know what's in front of us.