150 Cleaning Up Your Mental Mess: Mind Over Matter, Without The Woo

We dig into the difference between mind and brain, map the four levels of mind, and show how thoughts shape the body through neuroplasticity and epigenetics. Using tree and pruning metaphors, we share how to spot signals, trim toxic patterns, and prepare for the Neurocycle tools.

• Mind as thinking, feeling, and choosing
• Clear split between mind and brain
• Four levels of mind and their roles
• Thoughts as trees with memory branches
• Signals from the body as useful prompts
• Epigenetics and how thinking affects genes
• Reactive versus proactive mind management
• Pruning toxic thoughts to free up energy
• Kintsugi as a model for meaningful repair
• Tease into the five-step Neurocycle next week

Next week, the practical application of the neurocycle, we're gonna dive into those five steps

Transcript

Welcome And Book Setup

SPEAKER_00 1:17

Welcome to What's on Your Bookshelf, a life and leadership podcast where we live out loud the pages of the books that are on our shelves. With your host, Denise Russo and Sam Powell.

SPEAKER_02 1:29

Hello, everyone. Welcome back to another episode of What's on Your Bookshelf. This is our life and leadership podcast where we're living out loud the pages of the books that are on our bookshelves. My name is Denise Russo. My co-host is Sam Powell. We are going through a book called Cleaning Up Your Mental Mess by Dr. Caroline Leaf. This is a book that has five simple scientifically proven steps to reduce your anxiety, stress, and toxic thinking. Today we are going to be talking about thinking and all about what is in the mind or what is the mind. This is chapter six of the book. And Sam, I can't believe if I look at the spine here, we're more than a third of the way already done with this book.

What The Mind Is And Isn’t

SPEAKER_01 2:11

I know we're almost halfway there, actually. It's uh it's getting there. Um yeah, and it's interesting because we're still just we're at the towards the end of part one. Um, and part two is all about the actual system, like how to do all of the things. And this is sort of following along after the research, after understanding kind of what that looks like. But this transitions into what really is the mind and how to understand that. And that foundation, I think, like I've read this chapter, becomes really important in understanding how you can really take control of it. And I think she's got some interesting analogies that she uses. I mean, I feel like this was this is a very complex idea and topic. And I feel like she did a really, it's one of the easier ways I've felt to like understand this, but still be like grounded in, you know, kind of this the neuroscience of all of it. So it's it, I don't know, this is a really interesting chapter. I have a lot highlighted, and it even has some fun pictures. It's got a whole thing of a neuron and a synapse, like telling like showing you like, I don't know, diagrams on how things work, which was interesting and did sort of help conceptualize, you know, what this looks like. But um, yeah, it was uh this is an interesting, an interesting chapter because it starts out with what is the mind. It can be a tricky concept, so it's best to start with what the mind is not. Your mind is not your brain, your mind is separate yet inseparable from the brain. It uses the brain and the brain responds to the mind. The brain doesn't produce the mind, the mind changes the brain. People do things, our brains do not force us to do things. Yes, there would be no conscious experience without the brain, but experience cannot be reduced to the brain's actions. Super interesting.

Four Levels Of Mind Explained

SPEAKER_02 3:56

I really liked this chapter. I feel like even though it is a complex book and it's a complex chapter, she did make it, she wrote it in such a way that was understandable. I'm sure we'll get into it in our chat today about when she talks about a tree and the roots and the branches and the leaves. What I what I liked about the part right after what you just read to us is that we often think of our mind as our brain, like you just said, but we also think of our mind in a conscious state. And she goes on to talk about how there's three levels of our mind. There's the conscious mind, which is where we're thinking, where we're awake, what we're paying attention to. There's this the non-conscious mind, which is also while we're awake, but it's working 24-7 all the time in the background. And then there's the subconscious mind, which I didn't realize there was a difference between a non-conscious and a subconscious. And she was saying that the subconscious mind is between the two, it's sort of a tip of the tongue feeling. And then there's actually a fourth called the unconscious mind. It's what happens like when you're dreaming. And so, as I was reading through this whole part, I was thinking about how we always talk about the idea that if you want a different result in your life, that you have to investigate your actions, but that you also need to look at your belief systems and the way that you're thinking and choosing, and that those show up in ways that give or give you not the results that you want. And so she actually talks a little bit about this that you have the ability through neuroplasticity. Remember, last, I think last week we talked about you can become a neuroplastician of your mind just by controlling how your mind is sending signals into your brain. And to simplify that for me, I started thinking about these two verses that have always struck me, Sam, that I've studied for a long time, ever since I was a young girl. And they're both from uh the Bible, but they are based off of as well. There's a quote at the beginning of the chapter from William James that said, Man can alter his life by altering his thinking. There's a couple of different things that are in the Bible, like as a man thinketh, so is he, or what is what you think in your heart then becomes true. There's actually a book called As a Man Thinketh. I feel like James Allen is the author of that book. It's really old, old book. But there's this one verse in Romans that says, Don't be conformed to the world, be transformed by the renewing of your mind. And by testing that, you'll discern the will of God. And there's another verse in Proverbs that says, Your inner thoughts define you. What you think in your heart becomes real. And so it's almost as if thousands of years ago there were these people writing these things, and now we have scientists saying that this is all true based on what we're going to go through today, which is about how your mind is made up of trillions and trillions of thoughts and all the different things that you were just describing in the in the pictures that are in this chapter.

SPEAKER_01 7:06

Yeah. Um, yeah, and and I I I think one of the things that I found really interesting is she starts to explain like really what is you know, what is the mind and what is a thought. But she talks about our our mind characterized by a trend of thinking, feeling, and choosing. I think that's important to really understand is like we when we're thinking about how the mind works, it's it's those three things, right? Like we're thinking something, we're feeling something, and we're making a choice. And these things are happening very quickly over and over again. But I think that that's an important thing to really understand as we move forward. And when I think about the mind and I think about thinking, that's such an I haven't heard it explained that way before. When I think about like what really is your mind, when I think about those three things, that that's interesting. Especially the concept of choosing with it, right? Like I think I feel, okay, like I can, I could, I would normally probably come around to those as that's part of my mind. But the choosing part of it is interesting. And the more I think about it, I think the more that that makes a lot of sense to me. Because it's not just that like the thought processes, the feeling processes, it's that, you know, when I think about what my mind is, it's the choices that I make from that. And whether those are like conscious choices or subconscious choices or, you know, whatever, right? Like, you know, that that's that. But I think that that's really interesting. And and she talks about a thought as like a real physical thing that occupies mental real estate in the brain. And then she's got pictures of what a thought actually looks like, which is super fascinating to me. And I didn't think of a thought as something that takes up physical aspects of it. Um, but the thing that I found ultra fascinating about the thought part is itself is she said, like, the thought is really like the big picture, and then the details of the thought are all memories that you've got in there. And she catches those into informational memories, emotional memories, or physical memories. So if you think about something, and like I think the example she gave is really a good one of I'm concerned about a family member, like that's the thought you've got in your mind. But inside of that thought are all of the memories around why you're concerned about that family member, who that family member is, all the experiences you've had with them, all the feelings you've had about them, all the feelings you've had about the reason you're concerned about them, and everything you know about that concern about them, you know, and all of this. And so it's really interesting when you think about a thought, as simple as, oh, I'm concerned about somebody, right? Like that doesn't seem, you know, anything like ultra complex, but if I think about it in terms of like it's the thought, and inside the thought is all the memories associated with that, like that is that's interesting. That was just fascinating to me and a really interesting way to think about what a thought is in a way that I just had never, I don't know, even considered before. Like I'm I think I know that subconsciously, like deep down, but to really, I don't know, bring some understanding and enlighten, like light, you know, enlightening to that. Like that's just, I don't know. Like, I what was your thought on what a thought really is? To me, it was just one of those like moments I sat back and was like, oh my gosh.

Thoughts As Trees And Memories

SPEAKER_02 10:37

I was really awakened in this chapter because she uses an analogy of plants and roots and trees. And I could I could understand the science of it based on the way she described it, because she was saying that your thought thought your thoughts are like a planted seed, and that seed forms roots, and roots appear above the ground and grow and change into whatever the plant is, but our subconscious mind is like the root system that's underneath the ground, and that your thoughts grow and change over time. And so whatever we think about the most is what grows. Going back to those quotes I was talking about earlier. If you it's this kind of like a positive intelligence thing, right? As well as which is prioritizing positive thoughts because those grow, it doesn't mean negative thoughts aren't there, but you can diminish the growth. It's like, didn't we have an episode? I don't know what book it was, Sam, but where I was telling you about my cousin that did an experiment with plants. Yeah. Yeah. And so the idea with that was that if you water a plant and you speak life into it, the plant will grow. If you water a plant and you speak ill towards that plant, it comes from the concepts from a Japanese scientist that did a book about the uh impacts of energy in water droplets, right? Because you have that book too, I think. So whatever you think about the most will grow. Your emotional and physical warning signals that we experience, things like anxiety, warning signals, uh a sore stomach, aching muscles, these are like the warning signals that are coming from under the ground. If you imagine the roots under the ground of a tree that sprout into the trunk that tell the trunk whether or not to feed or starve the branches and the leaves. So what I took from this chapter is really understanding that thoughts are like branches and leaves and the memories that come from those thoughts. And if you want to have a healthy, thriving, uh robust tree that produces life and maybe fruit or flowers or whatever, then you have a choice to how you nourish that tree.

SPEAKER_01 12:48

Yeah, absolutely, absolutely. And uh and I I liked her tree concept that she uses because I do think it helps just, I don't know, maybe make it a little easier to to grasp really what's going on with our mind. Because when you think about the complexity of your thinking and these different levels, right? The conscious and the subconscious and the um, you know, these these different spaces, it's you just think about how much is really going on. And to me, it like it kind of feels a bit overwhelming, right? When I think about how much is going into every single thought, a conscious thought that I have, not only not even touching the subconscious thoughts that I have, it's almost like it's so much. And she talks about numbers, right? We have an estimated six conscious like bursts, like thoughts per minute. So 360 an hour, 8,460 every 24 hours on the conscious level. And on a non-conscious level, intelligent thinking occurs at about a million operations per second. Per second. Per second. It's faster than the speed of light. Like your brain is moving faster than the speed of light at all times, which is insane. And to me, it's like you think about how complex a thought is, right? All the memories, all of that stuff that goes into the conscious things I'm thinking, it feels overwhelming. And like, how can I possibly ever do anything with that? Right. It's so big and so much that it almost feels like no wonder nobody tries to manage their thoughts, right? No wonder we default to just like letting things happen to us because it feels a lot easier than trying to take control of 9,000 conscious thoughts and millions of unconscious thoughts and and really getting into those levels. But I mean, that's what she's that's her claim in this book is that no, you can, right? Like you absolutely, you absolutely can. And she talked about like where thoughts are located, how they're they are ingrained in the brain, they are ingrained in the mind, but also at like the cellular level, too. And I thought that was really interesting, right? And her research, we had talked about the research, right? It does show that, you know, there is that these things are are happening and are showing up in in cells and blood and genetics and all that kind of stuff. And she does round that out here of, you know, where do our thoughts live? Where where is all of this stuff stored? And it's not just we like we like to think about it as just in our brain, but it's in our brain, it's in our mind, and it's in our body itself, down to like the genetic level. And she talks about something called epigenetics, which I've never heard of. But this is basically what switches on and off our genes. So, like, if anybody, I've I've done a you know quite a bit of reading up, and and genes are fascinating to me. Um and it's interesting because we're learning so much about genetics, right? That's the research that has come along in that in the last few decades, is insane. And it's just one of those things like, I just can't wait to see what more we learn in my lifetime in the genetics space. But this is interesting because genetics, what she's saying is, you know, as long as we're alive, genes are constantly being switched on and off by the mind. And what we put into and onto our body, which could be passed through generations as predispositions, but also just in what we're doing in our own like thoughts and things like that, like you can actually turn flags on. So it's one of those things where like we hear us talk about like you have a pre genetic disposition for something, right? Like, you know, there's all those screens that you can do out there in the world, and it's like you're pre-disposed, predisposed. Why can't I say that? You have a predisposition for um something, right? A disease, a whatever. But what she's saying is there's a lot of control that we've got over whether or not that gets flipped on, not just from like the environment around us, but from how we think and manage our mind itself. And to me, that is fascinating. And again, like it kind of helps ground me out of this space of there are so many thoughts going on that I feel out of control into a space where okay, I actually do have a lot of control in this.

SPEAKER_02 17:30

Yeah. She says that the power of thoughts is almost incomprehensible because it impacts the level of your DNA and chromosomes in your cells. This is the science behind what she's saying, is that this is not, like we said last week, this is not woo-woo. This is about the science of our thinking. And she says if you constantly recall negative thoughts with embedded memories, so those are like the branches and the leaves on the tree, you will damage your DNA. And that creates a vulnerability in our body to disease. And so I think we said when we first started the book, this book will scare you if you don't take it seriously and do something to take control over your thinking. And as we segue into maybe the next chapter, she talks about how whatever we think about the most grows because we're giving it energy. And so you decide again what kind of fertilizer and nutrients and water are you putting around your tree.

Overwhelm, Numbers, And Control

SPEAKER_01 18:30

Yeah. And this next chapter is the interconnected mind. And it's really talking about now that we understand the mind and thoughts, right? How everything's connected together. And it's really just the concept of you can reactively deal with your mind or you can proactively deal with it, right? Pretty really get into like the preventative medicine. And that's what she's setting up these five steps of the neurocycle to really be. Is there the proactive, preventative medicine for your brain to really protect that? And you know, she's got a nice division of the levels of the mind that you were talking about. Um, and again, like if you're thinking about that tree, the conscious mind, the thing that you're fully aware of, right? That's where the six thoughts, the second two are happening, um, are like the leaves, right? They're the big, the big things that we see, the subconscious mind, which is that prompt um from the non-conscious mind uh to the conscious mind. So this is that connectedness that she's talking about. And then there's the non-conscious mind that's like the roots. So the subconscious mind's like the branches and the um trunk. So if you think about a tree, right, you've got your conscious thought, which is all the leaves, you've got your subconscious mind, which is the branches and the uh trunk, and then the non-conscious mind, which is all the roots. And so what she's saying is the conscious mind, which is that fully aware state, and the non-conscious mind, like down in the roots, is where thoughts are dynamically interacting and all entangled. This is just like you're not thinking about this stuff, it's just all the things that are happening all the time. But the subconscious mind in between is what prompts from the non-conscious mind in the form of emotional information and physical warning signs. This is where we start to feel, right? And this is the interconnectedness. The subconscious mind brings forth the feelings that we've got where our unconscious mind or our non-conscious mind is trying to communicate with our conscious mind, right? Like all of a sudden I'm feeling anxious about something. Well, why am I feeling anxious about it, right? Something's going on in that non-conscious section of my mind, and it's trying, it's screaming at me to tell me something, or my chest feels tight all of a sudden, right? I feel the physical symptoms of it. It's like, well, why do I feel this way, right? And it could be a positive thing too. It could be like all of a sudden I'm all excited. Why am I excited? My heart's beating really fast. It's like, oh, because this person is coming over and I'm excited to see them, and I haven't seen them in a long time, right? Like, this is all that communication. And so when you think about these levels of your mind, you've got these kind of three big ones. The conscious is where all those thoughts are going, but the non-conscious is where most of the activity is happening, and your subconscious is the thing that connects between the two of them.

SPEAKER_02 21:16

So the non-conscious, you can't see it. You don't necessarily feel it until it manifests itself into the conscious. She says, in order to make changes in our thoughts and subsequent communication, we need to be strategic, proactive, and deliberate about our thinking. And so, again, it's talking about how if you can't feel it, see it, uh, know about it, but you could still learn how to control it. It gets me to thinking about I saw this video this morning. There was a guy who I don't know why I keep getting videos about people who are pruning orchids. I am not a green thumb.

SPEAKER_01 21:54

But you're you watched one and now you're now you're seeing it. And now I see all of them.

SPEAKER_02 21:57

Yes. I literally watched probably one because I had they all die. They die. And so in this video, the florist had a person come in and they gave him their plant and said, I can't take care of it anymore. The leaves keep dying, it's not producing flowers. So he took the orchid and he lifted it out of the pot that it was in. And it immediately looked like there were no roots. But what he saw was that around the roots, there was a coconut shell uh uh hiding the root system. Once he removed the coconut shell, all the roots were entangled, like how you were just saying, the non-conscious mind is entangled thoughts. And then he had to remove all this moss off of the root system. And after he removed the moss and was showing on the video, like, okay, now look, here's the healthy roots, here's the ones that are completely dead, and here's the struggling ones. And so then he went like full on barbershop and started trimming all the roots off. And I was like, oh my God, you're gonna kill this plant worse than it already was. And he's like, nope, you have to do this to have a healthy plant. And so So he was snipping away, snipping away. And he's like, Look, these dead ones are sucking away nothing, but they're just dead. The ones that are sick are sucking the energy away from the good ones. And if you don't get them healthy, they are going to kill the plant. So he was deciding like which ones that were sickly were good enough to revive versus just chop off. And it really goes to what this is saying is that you don't have to be captive to your thoughts. You are capturing your thoughts. And so as the gardener or as the florist, he was making a conscious decision about the healthy state of this plant. So after he got it all cleaned up, Sam and he wrapped it back in fresh new moss and soaked it in water and everything else, there was still this like stalk that was green that typically you'd say, don't touch that because that could produce flowers. He takes the clippers, clips off the thing. I'm starting to have heart palpitations because I'm thinking, now this thing there's now, where's the flower? And he's like, Nope, we're gonna start fresh because now that the roots have the ability to breathe and the roots have the ability to process what's been done to it, there's a little shock that happens first, but then once it settles, it's gonna thrive. And it's the same thing in life. You have something that maybe so-called bad happens to you, and there's a shock. But you get removed from a situation. Maybe you were laid off, maybe you ended a relationship, maybe you have a really big change happening in your life with your family or your job or whatever it is. And there's a little bit of a shock. But if you don't clip off the dead parts and heal the pieces that are sick, then you are damaging all the good parts that are also still there.

Epigenetics And DNA Impact

SPEAKER_01 24:46

Yeah, yeah, absolutely. That's such a great analogy. And I think that that's that's really what she's getting at, right? With a lot of this, is like you've got the ability to realize there's a coconut shell keeping off your uh roots and your um non-conscious, you know, thoughts really trapped. And some of them are are bad for you, right? And it's creating this cycle of really perpetual toxic thinking. And you know, that this is what you've got to take control of. And she says that, you know, the the non-conscious mind's a incredible, but it's often misunderstood. And I thought it was fascinating. She said the conscious mind lags behind the non-conscious mind by at least 10 seconds. So it takes 10 seconds before you're consciously aware of what's going on, and it and it's roughly in this 10 seconds that the truth of the situation will try to get your attention through emotional and physical warning signs, right? So, like your little orchid, right? You're seeing these signs that something's not right, right? Something's not right below the surface in you know how this plan is going on. And and for us, like we're constant, like again, we are constantly so fast processing stuff that that's what at the end of the day, like, this is what emotions are doing. These are what these physical reactions in your body are doing. They are trying to get the attention of your conscious mind because you can only really focus on one thing at a time, really, right? You might be processing a lot, but like you've got to draw you would draw attention to a thing at a time, really. And so this unconscious part that's processing all these thoughts and with the have all these complex memories in them and saying, uh, hey, are you are you seeing this? Like I'm seeing this. Are we seeing this? Like, come on, get on board with me here that this is happening. And that's really where she says that the work is worth it, right? Is is really getting down into drawing attention to, okay, something's trying to get my attention, and I need to go fix the roots of it, right? Because that's where so much processing happens so that it flows up into this interconnected subconscious and conscious mind.

SPEAKER_02 26:51

She says whatever you experience in your mind will also be experienced in your brain and body, and that the more you can understand the non-conscious mind, the more you'll see that you have the ability to change your mind. I really want to encourage everybody listening, because we only have a short amount of time every week here. Go watch Disney Pixar Inside Out and Inside Out 2. It exactly explains in an animated, kid-friendly way that's super deep. Every time I've ever re-watched the movie, I learn more and more about neuroscience. And it talks about these ideas of that grabbing attention, like you're saying. There's these characters that are the emotions of a young girl, and they all want her attention. And all of those emotions do manifest in her body with things that she's experiencing joy, happiness, sadness, anxiety, frustration, fear, whatever those things are. And it's all energy. And so it's important to remember that throughout the process, the author says energy is never lost. It's just transferred. It's the basic law of physics. So if you have an ability to decide how to transfer your energy and you can learn how to do it through her five-step process, which we are going to get through eventually in these chapters, then you are going to be able to apply this, which is what's going to happen next week when we dive into part two of the book, which is the actual practical application of the neurocycle. I think for me, I'll end um with one thing I took away at the end of this chapter that is something I experienced in a lesson that I learned once. So she talks about how there's this idea that if something happens to you in life, it isn't the end. It can become something really beautiful. It's sort of even like the obstacle is the way in a in a way, which is that there are things that are going to come into your space in your life that are difficult, hard, or even the the um the happiness book um with the guy who lost his son, um, was solve for happy.

SPEAKER_01 28:55

Solve for happy, yeah.

SPEAKER_02 28:56

Solve for happy. That was a bad situation that he turned into something good. And so she talks about this concept, which is Japanese called Kinsugi. And my pastor did this lesson at church years ago. It was like a leadership development lesson about how the ideas in in Japan, if there is a piece of pottery, and it might even be an inexpensive piece of pottery, if it gets broken, these artisans take this broken piece of pottery, they put it together with gold and they paint these intricate designs with this gold glue, I guess. And these pieces are now on display in even museums, very, very expensive artwork. And it's all because they took the brokenness of something and created something beautiful out of the broken pieces. It doesn't mean that it was exactly the same as it used to be, but it's something that was similar to the way it used to be, but now it's even better and more, more valuable.

SPEAKER_01 29:54

Yeah, yeah. And I uh I got this gift from my mom. My mom is a um is a nurse, but she studied developmental psychology um for a long time. So she was always interested in like how does the brain work and all that sort of good stuff. Probably where I get a lot of my curiosity from. And um, I found this thing on Etsy years ago that was this painting of the brain. It was in black and white, it looked like a pencil, you know, drawing of like the brain, but it was a Kinsugi drawing. It had the gold like leaves through it. And I just thought it was just this beautiful picture. And at the time, my grandmother had um had just lost her battle with Alzheimer's, and um, you know, and so it just reminded me a lot of of that, of this. But I think that that's really like what this is all about, right? She says that, you know, whatever we think about the most grows because we're giving it that energy that you talked about. And at one point in this chapter, she says, at your core, you are wisdom. And I think that when I think about it, and if you don't know what Kinsugi is, you definitely should Google it real fast because it's beautiful, right? Like it's absolutely gorgeous. But I like to think of our mind in that too as like sometimes things feel broken and we feel like we get broken, but you can restitch yourself together in a way that's more beautiful, that is unique and different and maybe stronger and more powerful than you were before. And you've got so much power in that. And I like I can't wait to get into this second part of the book because this is where the rubber meets the road, right? Of the practical application and ending this. And I, the more I read this book, and the first this is probably a little over half the book, is the first part of the book, it's just convinced me like how desperately I need this, and just everyone I know and care about and love and want to have a happy and healthy and full life need this. And so I hope that people join us in the second part of this journey, especially. Like, I hope you understand the urgency from these discussions you and I have had, because I think that this is where you and I are with this of like, I need to fix this right now. I need to fix, fix this, you know, that process mind mess that I've got going on, because it's imperative to me living the life that I want and just living period. And so I can't wait to get into that because I need to know how I take control of these millions of uh you know, non-conscious thoughts are going through my my head here and um making them unmessy.

Reactive Vs Proactive Mind Management

SPEAKER_02 32:29

I'm so grateful to always be here with you every week, Sam. I'm grateful to our listeners. Dr. Leaf closes this chapter by even saying that we need to be discerning about who we connect with and who we listen to because we can quite literally enhance or damage each other. You always enhance me, Sam. I'm super grateful for our friendship. And Dr. Leaf says thoughts and ideas from other people, including what we hear, read, and watch, have the potential to exert a controlling influence over our thinking, feeling, and choosing if we let them. So I just want to close by saying thank you to you.

SPEAKER_01 33:05

Yeah, same. I feel the exact same way. I love that we get the time to do this every week. And that's one of my favorite, most enriching parts of every week for me. And I I've said it a million times. Like I would do this even if we weren't recording and putting out there for other people to come along the journey because it just helps me and changes. I think it changes the trajectory of my life. And that is all because you invited me a few years ago, and I will forever be grateful.

SPEAKER_02 33:33

Oh, same. Well, on that, I'll give you a virtual hug. Listeners, we're giving you virtual hugs, Love Fest all the way around for changing your mental mess. Next week, the practical application of the neurocycle, we're gonna dive into those five steps. But for today, my name is Denise Russo, and on behalf of my friend Sam Powell, this has been another episode of What's on Your Bookshelf,