Discussion of the History of Neurobiology

In PZ’s class we’re reading and discussing Soul Made Flesh by Carl Zimmer. This non-fiction book follows the journey that neurobiology has made throughout its history. The details of this history that most prominently catch my attention are the logic, methods, and observations upon which early discoveries were built.

Plato got the ball rolling with his theory that the body consists of three souls. The human soul resides in the head where it can sense surroundings and and divinely reason about their meaning. The vegetative soul resides in the abdomen where it initiates growth, lustful desires, and so forth; and the vital soul resides in the heart where it radiates love and compassion. (Zimmer, 2004) Plato’s theory of souls was based primarily on thought and reason but is well considered and worthy of being scribed into one of the first pages of history.

Aristotle (Plato’s student) dissected a vast array of animals, most likely seeing the importance of taking it apart to see what’s inside in understanding how they work. If I myself were, for example, asked to draw a diagram of the inner workings of a wrist watch, I would fail miserably. A few centuries after the time of Plato, Galen gained a further understanding of anatomy by studying the massive wounds sustained by gladiators. The works of Aristotle and Galen remained the dominant teachings for well over a thousand years.

Gradually, around the 17th century, new ideologies began to refute the traditional teachings on human anatomy and the mind. Descartes published Discourse on Method which presented philosophical arguments about thought and human existence. William Harvey introduced the controversial idea that blood circulates through vessels. Thomas Willis, Robert Boyle, and other members of the Oxford Circle began laying the foundations of modern neurobiology by carrying out progressive experiments that no one had ever thought of before. (Zimmer, 2004)

How exciting it must have been to watch, first hand, the beginnings of this intricate science unfold. I sometimes think about what sort of contribution, if any at all, I could have made if I could somehow have been a student at Oxford hundreds of years ago, bringing with me my limited sophomore understanding of chemistry and biology. I’m excited to continue reading Soul Made Flesh to see where history goes from here. If you haven’t read this book, it provides an excellently thorough account of neurobiology from the very beginning. I will be sure revisit this subject as I continue to read and as we continue to discuss it in class.


Zimmer, Carl. 2004. Soul Made Flesh. Free Press, New York, NY.


  1. silence says

    I’m not sure I’d start with Aristotle and Plato when it comes to any kind of beginning in ancient studies of the natural world. Doesn’t it make more sense to start with Thales?

  2. says

    You could go all the way back to the Ebers papyrus (circa 1550 BCE) and the Edwin Smith papyrus of perhaps a half-century earlier. Egyptian medicine of the era was clearly founded on some amount of real-life observation. When you cut corpses up to take out their organs and make mummies, you have to be learning something about human innards.

  3. Xzanron says

    Yes, I’m sure those days were very exciting. Nothing beats the rush of adrenaline and the sense of total relief that you’ve just managed to escape the religious lynch mob that wants string you up for dissecting bodies to find out what’s going on. “Certainly he must be the devil.”

    You are right though that it is a fascinating subject and I know far too little about. One of the reasons I hang around here :), that and the cephelapod porn of course.

  4. says

    I also pine for earlier ages and wish that I could have been present for some of humankind’s great discoveries. But don’t count this modern era out from lack of interest or significance. The truth is that we are living in an age of truly astounding accomplishment and understanding. There are still new horizons and we are pursuing them at a constantly accelerating pace.
    I know it’s not biology, but here’s a wonderful example of science still in motion:

  5. Shaun says

    If you’re interested in more modern neuroscience history I’d suggest picking up a copy of The Changing Brain: Alzheimer’s Disease and Advances in Neuroscience by Ira B. Black, especially if you want an overview of alzheimer’s history. It’s a good read, especially if you are new to neuroscience, although some of the info is out of date since it was published 5 years ago.

  6. says

    Blake [2]–The Egyptians did see the brain when they embalmed the dead, but they just ripped it out of the skull with a hook jammed into the nose. They preserved other organs in jars. They particularly prized the heart, which they thought would be put in a balance to determine the fate of the soul.

    This sounds weird to us, but only because we live in such a “neurocentric” world. If you looked at the decaying mush coming out of a cadaver’s head and didn’t know better, you might not think much of the brain either.

    For more information on the pre-scientific revolution view of the brain, you should check out Stanley Finger’s books–The Minds Behind the Brain and the Origins of Neuroscience.

  7. says

    Does PZ have some sort of deal going with Carl Zimmer to keep his sales figures afloat?

    If so, it’s working! Just ordered my copy of Soul Made Flesh on Amazon and look forward to reading it.

  8. says

    Yes, I also picked up a copy of Soul Made Flesh a couple weeks ago and am thoroughly enjoying it. As enjoyable as learning about the history of neuroscience is, having it presented by one of my favorite science writers is even better.

  9. Physicalist says

    @Carl Zimmer (#6)

    The Egyptians did see the brain when . . . they ripped it out of the skull with a hook

    I seem to recall hearing about someone who (fairly) recently took a corpse and went through mummification process with the tools of the ancient Egyptians. If I recall correctly, he concluded that people were wrong to assume that they pulled the brain out with the hook. Instead, he concluded that they basically scrambled the brain like an egg and then just turned the head and let it pour out.

    But it’s been a long time since I read the account, and I don’t have too much experience with brains. (Though my limited experience does make it seem unlikely that one could hook it and pull it out the nose . . . )

  10. Physicalist says

    And didn’t Aristotle likewise think that the brain had nothing to do with thought (wasn’t reason in the soul)? I seem to recall that he thought the brain was a radiator for cooling blood.

    @silence (#1): Given how little we actually know about Thales (and the other pre-Socratics), starting with Plato and Aristotle seems pretty reasonable to me.

  11. says

    Carl Zimmer:

    The Egyptians did see the brain when they embalmed the dead, but they just ripped it out of the skull with a hook jammed into the nose. They preserved other organs in jars. They particularly prized the heart, which they thought would be put in a balance to determine the fate of the soul.

    I had a serious Egypt fixation in fourth and fifth grade, so that’s hardly news to me! :-)

    Of course Egyptian medicine was limited and their biological discoveries error-prone; that’s not much of a surprise. What I find more interesting is the question (probably unresolvable, but what the heck) of why it took so long for civilization to come up with a Thales, an Aristotle or a Galen. The Egyptians certainly had no compunctions about cutting up dead bodies, so what about them prevented them from gaining a knowledge of anatomy as good or better than the dissectors of Hellenistic times? Were they just too concerned with preparing the body in the proper way, and had no interest in figuring out what the different pieces did?

    Thanks for the book recommendations, by the way — I really enjoyed Soul Made Flesh!

  12. says

    I suppose I should have made more clear that I was talking more about the origins of evidence-based investigation, rather than the study of the brain specifically. Since lots of people early on argued that the “seat of reasoning” or of the emotions was in the heart or in the liver, I don’t want to get too neurocentric.

  13. says

    Hi Blue Expo,

    You wrote…

    I sometimes think about what sort of contribution, if any at all, I could have made if I could somehow have been a student at Oxford hundreds of years ago, bringing with me my limited sophomore understanding of chemistry and biology.

    While I don’t want to read too much into your wistful thoughts about the past (understanding history is important), I would think this would be an exciting time to be a scientist, especially a Neurologist.

    I will give you the short version my Quantum Quackery. You can find a longer version here

    Scientific knowledge and tools have advanced enough that we can start putting all the pieces together. Cosmology, Quantum Mechanics and Biology are all merging. For example, DNA strands are being used to build quantum computers. Large-scale General Relativity is being used to explain things at the quantum level.

    Sir Rodger Penrose and Dr. Hameroff have a hypothesis called Orchestrated OR model of consciousness. It is an effort to tie these different scientific disciplines together. There are a lot of people who don’t like its implications. I suspect PZ Myers is one of them. However, I think it would be fantastic if Neurobiology turned out to be the key to solving major unsolved mysteries in all the sciences.

  14. silence says

    Physicalist: I agree that we don’t know much, but its a mistake to ignore the presocratics simply by virtue of having lost most of what they had to say, or to talk extensively about Aristotle simply because an accident of preservation left us his esoteric writings.

    Maybe the right solution in this kind of discussion is to make a brief mention of the ancients, and then move on to the sequence of early modern scholars whose work led much more directly to our current partial understanding.

  15. Vasha says

    A book that has quite a good discussion of the presocratics, though mostly concerned with their thoughts on cosmology, is The Grand Contraption: The World as Myth, Number, and Chance by David Park.

  16. thwaite says

    The ancient Egyptians’ treatment of brains during mummification is pretty fully discussed at another scienceblog by Shelly Batts, a neurosci grad student at U. Michigan. Lots’o’lurid details, tastefully (no, not that way) presented.

  17. says

    Silence [#17], I’m with Physicalist here. Thales should get a token nod as an early philosopher, but we can essentially forget about him. According to Albin Lesky (A History of Greek Literature, J. Willis and C. de Heer, trans.), “We have of course no knowledge of Thales’ conception of the soul. Consequently his statement that the magnet has a soul may refer to nothing more than a force capable of producing effects. He is also supposed to have said that everything is full of gods: a statement (whether truly his or not) which could serve as a trade-mark of this early philosophy.”

    Also, back to Blue_Expo’s post: Examining Plato as a source of neurobiology seems to be as useful as studying Thales. Great as he was, Plato was far from scientific (in the modern sense – for an ancient he was about as good as they got pre-Aristotle. Using the Delphic Oracle as a starting point to prove one’s wisdom probably wouldn’t fly today).

  18. Dr Benway says

    I’m getting all nostalgic for Aplysia. Ah the La Jolla tide pools, a bucket, and the early morn’.

    You can have all sorts of fun with a nervous system dissected out of a sea hare. But you must mind the dye.

  19. sailor says

    “I sometimes think about what sort of contribution, if any at all, I could have made if I could somehow have been a student at Oxford hundreds of years ago, bringing with me my limited sophomore understanding of chemistry and biology.”
    A game I sometimes play is to imagine myself dropped back a couple of centuries, with the knowledge I have today and see what use it might by to me or those back in those times. Thee are of course no Ace hardware stores around. My general concusion is my advanced knowledge would probably get me laughed out of town.
    At any stage in science we tend to think we have really made all the big breakthroughs and only mopping up is to be done. ButI think opportunities to discover something big in science are probably greater today than at any time before.

  20. Dave S. says

    Physicalist [#9] –

    I believe you’re talking about Bob Brier, a.k.a. Mr. Mummy. The brain was difficult to remove from a skull without severely damaging either. So the Egyptians used the technique of breaking through the thin bone at the base of the crania, via the nose, and used the hook to swoosh around and then yank out the brain matter. They didn’t know what the brain was for, I believe they thought it may have been the source for nasal mucus. Makes some sense I suppose.

  21. says

    Thales is too far lost, but Democritus did have explicit opinions on the nature of perception, for example, which are still available to us. And Empedocles was the first to hypothesize evolution by natural selection. Finally, there was Anaxagoras and nous and Heraclitus and the logos all of which are psychology-history important

    (Does Zimmer’s book really say Plato started speculation about mentation, though?)