Thursday, April 21, 2011

Reflections on : A Treatise on Human Nature by David Hume - Part1 Section1

According to Hume in A Treatise on Human Nature (1740), there are two types of mental activity: "impressions" and "ideas". From Hume's comments, I would describe impressions as including all mental activity that is not an idea. This would include emotions, of course, but also physical and mental perceptions that occur while interacting with the world. For example, if you touch a hot stove, you experience hotness (the impression) independently of the idea of "hot".

Impressions and ideas can be "simple" or "complex". Simple impressions and ideas cannot be broken into component parts of other impressions and ideas. Complex ones can be subdivided into simpler parts.

There is a very close association between simple impressions and ideas - so much so that they may often appear inseparable in the mind.  When I touch the hot stove, I feel the hotness and think "hot" almost simultaneously. 

All simple ideas are preceded and derived from simple impressions. "All our simple ideas in their first appearance are derived from simple impressions, are correspondent to them and which they exactly represent." The impression comes first, then the idea. "We cannot form to ourselves a just idea of the taste of a pine apple, without having actually tasted it."

Complex ideas, composed of simple ideas (and their related impressions), correspond closely to complex impressions. "...all simple ideas and impressions resemble each other; and as the complex are formed from them, we may affirm in general, that these two species of perception are exactly correspondent."

In general, complex ideas can be linked to preceding complex impressions, just as in the simple idea case. However, there are exceptions.  Hume gives an example. Imagine you are shown a pallet of blue shades ranging from dark blue to light blue. One shade in the middle is missing. You can form an idea of what that shade looks like, even though you haven't actually seen it because you can derive the idea from the impressions of the blues on either side of the missing spot. So while there can be complex ideas not preceded by a directly corresponding impression, the idea is derived from a collection of impressions that closely resemble the idea. "Ideas produce the images of themselves in new ideas; but as the first ideas are supposed to be derived from impressions, it still remains true, that all our simple ideas proceed either mediately or immediately, from their correspondent impressions."

From my own analogy, I suggest we can form the idea of a number, say for example "152" because we have a prior impressions/ideas of 1, 2, 3 etc. I also suggest that this same process could be extended to the idea of infinity. I note that this logic seems to support Hume. While we can have the idea of infinity, it still leaves us uneasy mainly because we have never had the experience/impression of actual infinity.

Given this discussion of impressions leading to ideas, and not the reverse, Hume states that there are no innate ideas. They are all derived from our impressions. "...ideas are preceded by other more lively perceptions, from which they are derived, and which they represent."

As I was reading this chapter I kept think of the left brain / right brain theory - particularly that it would be interesting if you substituted those words into Hume's argument. I also thought about the books, Drawing from the Right Side of the Brain by Edwards and The Feeling of What Happens -  Body and Emotion in the Making of Consciousness by Damasio. Finally, I felt that Hume was weighing in on the always popular party question: was mathematics invented or discovered? His comment that there are no innate ideas seems to put him in the "invented" camp. I would disagree with him on that point.

Wednesday, April 20, 2011

The "Cheers" Book Club

We should all have a "Cheers" bar - a place where everyone knows our name - where we are accepted.

We all need - desperately need - to be accepted. This need drives so much of our life -who we hang out with, what we believe, what we do for a living. The need to be accepted drives our very sense of self. If we don't feel accepted, perhaps its because we are not worthy. Maybe there is something wrong with us.

Most of us counter this fear, this sense of worthlessness, by learning to (or at least pretending to) accept the beliefs of those around us. Sometimes learning to accept is healthy (such as Buddhist practice) - sometimes not so healthy. I will adopt my parents' goals so that they will accept me. I will accept a religious doctrine so that my church will welcome me. A professor will accept standard scientific thinking so that she herself will be accepted into the scientific community.

But what happens when you can't accept?

There have been a few points in my life where I felt so out of step with those around me that I began to truly despair. At one point, the split between what I felt was true differed so strongly from the commonly accepted that I began to question my sanity. The worst part of this was that I knew that voicing my skepticism and concerns would only drive me further from those around me.

I was in asset management at the time, and my concerns were about standard investment theory (which related to the nature of risk and returns, which is turn was based on an questionable view of the nature of reality....). Hand in hand with this non-acceptance of standard theory was my questioning of what was marketed as investment expertise. Questioning the theory of experts is roughly the same as questioning the religious doctrine of priests. It was a difficult time for me because I was constantly being measured by a standard I did not accept as valid. Yet my livelihood and my reputation depended on this measurement. [I will add by way of disclaimer that none of this related to actual investment strategy or performance. It related more to the perception of risk and return - pretty subtle point but perception is often more important than reality.]

What I needed was a friend - an outside voice - to tell me that I was OK. That I was not alone. I needed to know that there was a community out there in which I would be accepted.

I found what I needed. It was the book Fooled by Randomness by Nassim Taleb. About a chapter into this book I had a shocking revelation: "This guy is in my head! All of these rants and arguments that I have been keeping bottled up in my head are spewed out all over these pages. How could this be? This guy is crazy - just like me!"

There was so much of this book that truly was a rant - and I loved it. This guy Taleb knew his finance theory - I had read an earlier book by him called Dynamic Hedging. And here he was, someone with real professional credentials - ranting just like me.

I had no doubt that this book would be a failure. It was a ranting, poorly written book that challenged accepted concepts of risk and return in finance and in life. Who would read that?

Much to my surprise, Fooled by Randomness was a success and Taleb wrote an expanded second edition (with less ranting) and then the book The Black Swan. Taleb's success meant something special to me. Not only did I find a kindred spirit in Taleb himself, but there were a lot of other people out there who found his opinions worthwhile. These were my people! I was not alone!

So I found the acceptance I so desperately needed in a book. While I was reading this book a feeling of relief washed over me.  I was under so much stress, and while this book did not change the stress of my daily life, I could face the days a little more easily knowing that I was not alone.

All my life I have found comfort in books. I remember how meaningful the books of Hermann Hesse were to me when I was in high school (Demian, Siddhartha and The Glass Bead Game). And Ayn Rand's passionate cry of self-worth in Atlas Shrugged still echoes in me today.  If nothing else, these books (and others not mentioned) told me that I was not alone. I don't always agree with their views - but as people I respect and accept them - and I hope they would me.

Friday, April 8, 2011

I Stand Corrected

My last blog was me ranting about non-fiction "idea" books burying their key point too deeply - forcing me to read too much of the book before I could tell if it would be worthwhile.  One book I complained about was The Checklist Manifesto by Gawande. I realize now I was wrong.

If you bought a book titled The Checklist Manifesto, what would you think it was about? Checklists - right. And would the book have been in favor of checklists? - Yes! Of course! So there it is. The key idea of this book is that checklists are great. And this key idea wasn't buried deep in the book - it was right there on the book's cover.

The problem is, I assumed there would be more and kept looking, thinking that the golden nugget would be on the very next page. But no - the golden nugget was sitting on the book cover and I had just passed right by it. It turns out that the rest of the book was about medical and aviation stories where lives were saved through the development and use of checklists.

Part of me wants to start a new rant on people writing books based on one idea that could be said in 3 words: "Checklists are great". But just maybe there is something more to this idea and it deserves more than 3 words - even if it is simple.

I was tutoring a student in statistics last semester. He was an engineer and plenty smart, but he was struggling in his class. The exams involved word problems and were quite confusing for the uninitiated. After our sessions, he ended up doing well in the class and I think I really helped him. I think my best advice to him on the subject was this - I told him to go through this process on every exam problem: 1) Determine what kind of problem it is. You do this by looking at the data itself and looking for certain key words in the question. 2) Go to the spot in the software that addresses that type of problem - he should already have mapped out the software to know where to go for each type of question.  3) See what information the software asks for and see if it fits the data provided. 4) Assuming that is a yes, go to a prepared list of things the professor will look for to get full credit.

I know from talking to several students in the class that they study and learn the material, but during the exam, they get confused by the word problems and end up wasting most of the exam time wondering what to do or going down wrong paths. They end up not being able to finish the exam in time. My method takes about 3 minutes - if the person is prepared ahead of time - and should allow a student to finish the exam in about half the time provided.

The secret to my method was a checklist. Not that I thought of it as a checklist at the time, but that is what it was. I thought of it more as a decision tree, which is just an enhanced checklist.

All of this makes me wonder - where else could I use checklists? And why don't I use them more often? What kind of problems can be addressed with checklists? Do some people internalize checklists quickly and does this give them a huge boost in productivity and learning? (My guess is yes on that one) This sounds like the subject of a new blog.