Hello. Time for the fun to begin. And I'm going to start with what, what I think is a really kind of interesting story. It's a story about the relation of this concept we have of a soul to who we are, and how our views of that have changed over time, thanks largely to the combined contributions of Philosophy and Biology. So, let's get right into it. I've titled this lecture Psychology Emerges from the Shadow of the Soul, nice imagery there. and I want to start, well, actually, I'm not exactly sure where this starts. Because for literally centuries and centuries, humans have always perceived themselves as special in some way. distinct from everything else in the world around us. I think this is captured really well in a, in a song from the Police, where, where the chorus says, we are spirits in a material world. The idea there, the concept is that, sure, we live in this world where everything around us is, is perceived as physical, as material. But we are something else. We have a spiritual element to us that makes us distinct. Now, this distinction is really relevant in the scientific context for the following reason. Things that are physical, things that are material, we assume that the interactions, the behaviors those things show must follow what we call natural laws. And in fact, science is the pursuit of those natural laws. The idea that through careful observation and systematic manipulation, we can figure out what those laws are. Things like gravity, you know, and, and various other laws. and that in so doing, we'll gain a really good understanding of this physical world around us. And so, we studied Physics, we studied Chemistry, we studied Biology Astronomy, etc. all of those are studies of the physical world around us. But, of course, if we do not perceive ourselves as physical beings, if we perceive ourselves as spiritual beings, then what we're implying there is that our behavior does not follow such constrained natural laws. And if it doesn't, well then, it doesn't makes sense to study it scientifically. So really, psychology would never be born unless we started to think of ourselves in different ways and that process really began with Rene Descartes and here's a story of Rene Descartes that I really like. the idea is that he was walking through a park in, in, in France, and as a typical French park, it had statues and it had flowers. Up ahead he saw a statue of, of Diana, goddess of the hunt, beautiful statue. So, he started to approach to get a better look at her, but as he came closer out from behind the bushes came Neptune, barring a trident and blocking his path. A statue of Neptune, I should say, and that's what was, you know, really so impressive, the statue moved as if with intention. Now, how did it move? Well, this was the time when hydraulics was just being understood and used. And so, literally, Rene Descartes had stepped on a pressure plate which forced some sort of liquid through a tube and ultimately that force was used to move the statue on some relatively, relatively frictionless set of, you know, rails or something like that. That's how the motion actually happened. But in Rene's mind, it was a really profound experience for the following reason. He knew that statue was inanimate, he knew it was made of material, you know, physical material, and yet it behaved as though it was alive. That is, it was animate and had intentions. It looked like the statue was trying to block his path. So, Rene suddenly started looking at other things, like animals and humans, and asking whether maybe their behavior was analogous to that statue. Maybe they you really were physical beings as well and may be their behavior did reflect something like hydro, hydraulics, some physical process that made them look animate. Ultimately, Rene concluded that that once the case for animals, he felt they were fully machine-like, fully mechanical. But humans, he thought were a little different. Humans, he thought, had a dual nature. And we now call this notion, Cartesian Dualism. So, he thought, yes, humans are partly machine. And sometimes, their behavior is reflecting that mechanistic side of them, but he thought humans also had a soul. And that soul could, at times, control the body. Much like a, a marionette controller, you know, a puppeteer. the puppet is moving, the puppet is acting, but it's actually the puppeteer who's moving the strings and causing the action. So, Rene thought we do possess a soul and that soul can intervene and take control of this machine, or it can kind of sit back and let the machine do its own thing. So, this dual nature, Cartesian Dualism. As philosophers considered this idea, some of them went a little bit more radical. And I'll, I'll ask you to kind of look at the dates now. Rene Descartes, he's around 1600s. So now, let's go to John Locke, late 1600s. So, John Locke started to push the idea that maybe even the mind, the human mind, maybe it was even mechanical, physical and therefore, maybe it was subject to natural laws that could be studied scientifically. Now, this notion was given a name by James Mill, you know, into the 1800s now. James Mill called this idea materialism, the idea that we are material beings. So, material beings in a material world. And therefore if we are completely material, if there is no soul whatsoever, then everything, all human behavior, reflects material interactions that should be governed by natural laws that could be studied, okay? So, that's a, that cognitive shift really opens the door for psychological investigation. Now, before I go too much further, let me just say I have a link to a short video here that explains this notion of Cartesian dualism in, in a little bit more detail and, and it shows you some pretty pictures along the way. So, check that out and then come around right back. Okay, welcome back. Philosophy is all well and good, but Philosophy is about ideas. How do you know which ideas are right? Well, Philosophy itself had an answer to that question. And the answer was something they called Empiricism. Empiricism is the notion of conducting experiments that demonstrate clearly what is and what isn't true. And when it comes to this notion of, of humans as potentially being materialistic beings I want to highlight two sorts of experimentation. So, first let's start with Luigi Galvani. Luigi Galvani, a very interesting guy did a lot of research on frog legs or he eventually, at least, did. it was kind of happenstancial, he happened to have, I don't know why, he happened to have dismembered frogs on, on a table where static seemed to cause a leg to move. And he was intrigued by this, and he ultimately created a scientific experiment. So, that's kind of of shown in this panel on the right. These things that you're seeing are depictions of frog legs and, you know, what Luigi would stress when he did his demonstration is, there is no soul in these frog legs. Maybe, depending on your belief system, you might believe that once upon a time, a soul did inhabit this frog's body. But if that soul was there, it ain't there now. at some point, when this frog became dismembered, the soul left the body. And clearly, what we have left here is just biological matter, material matter. But what Luigi shows is if you apply a current, so imagine, this is a frog leg, if you apply an electrical current to the muscle, you will see that frog leg retract. And if you let that current go, it will kick it. So, by applying or not an electrical current, you can literally make that leg dance. You can make it look animate, you can make it move, as though it were full of life. There's a short little video, very short, but let's just do it for fun to give you a sense. Here, we have our frog legs, applies a current to one place and ground to another, you see the frog leg kick, okay? Nothing too profound there, but that gives you the idea and Luigi would go around showing this demonstration. It was very powerful. It showed people in a very clear way that the body at least seems to be a mechanical kind of device, not a hydraulic, more electric in what we will now call electrical, electrochemical. but clearly there was a machine like nature to it. Okay, fine. It's a frog. Rene Descartes said frogs were immaterial. Why should we be impressed? Why should we accept that what's true of the frog is true of the human? And that's where I want to highlight the work of Paul Broca. let me translate this for, for, for those of you who are not Chinese. this says, Broca's area, this says Wernicke's area and it's pointing to var, various subsections of the brain. So, let, let me give you the backstory of this. Paul Broca and, and notice now, we are into the 1800s. Paul Broca was a medical doctor and he would visit many different institutions and one thing he noticed was that, he came across these patients, in different places that seemed to have a very similar and interesting symptomatology. So, specifically, they would follow instructions well. If you, you said something to one of these patients like, hey, can you go get that glass of water on the table over there and bring it to me, they would do exactly that. They clearly understood language. But when they tried to speak to you, they couldn't form comprehensible sentences. Their language was all jumbled. They could perceive speech but they couldn't produce it. Paul found this really fascinating and he did what had to be a kind of an odd thing for the time. He asked these patients for their permission for the following. When you die, I would like to cut your skull open and remove and examine your brain. Kind of a crazy idea, but a number of patients agreed to this. Said, okay, sure. Well, I guess they didn't actually say, okay, because they had problems speaking. But they had some way of indicating that they were okay with this. And now, Paul being a very, very patient scientist, waited. [LAUGH] And he waited till they died. When they died, he removed their brain and looked at it, and tumor patient, everyone of them had damage in this area. This are we now call Broca's area. In fact, since Broca's work another patient group was was discovered as sort of opposite patient group who had problems understanding language but could produce it perfectly fine. When you look at their brains, they all have damage over here, in area we now call, Wernicke's area. Now, these results are critical because they seem to show that the brain itself is kind of put together like a machine. Distinct parts of the brain seem to have distinct functions, a notion that we call localism in the brain. Local parts of the brain do very specific things. That is true of machines. You know, the steering wheel does a very specific thing in a car. The acceleration pedal does a very specific thing. So, the brain kind of looks like that. And it looks like that even with respect to something like language, which we consider a very high level ability, a human ability, shall we say and even then, it looks mechanistic. So, the results of Broca really seem to go along with this, this philosophical move towards a materialistic view of humans. By the way, this was also the time, I have Frankenstein over here. Because I think it's kind of interesting to know, Mary Shelley's Frankenstein, that book, was written at about this time. And really, the fact that it's written about this time is a reflection of the time. This was a time when doctors, physicians, scientists, started to think of the human body and the human mind as a machine, something like Frankenstein, that you could maybe even put together with spare parts. And think Luigi Galvani now. If you have a bolt of electricity, that might animate this machine and bring it to life. And maybe that's all there is to a machine. Now, Frankenstein wasn't, you know, a real success as a human. But he does embody, quite honestly, that concept, that the human condition maybe a purely physical, purely material condition. And if that's true, then we can assume that human behavior must reflect natural laws and that put it squarely into the, into the realm of science. It suddenly becomes human behavior, suddenly becomes something we can study scientifically. That's what we'll turn to next. Thank you for your attention. I hope you enjoyed the story. Until next time.