John McCarthy Papers on Squid's Blog

Babar - A Little Language with Speech Acts for Machines

Tue, 04 Jun 2013 18:57:52 +0000

Preface: A Gentle Obsession

About a year ago, I picked up John McCarthy’s paper on Elephant 2000. I have to admit that I only understood about 10% of it. But I was so intrigued by the ideas that it sent me on a quest. I re-read it numerous times, slept with it under my pillow, and finally decided that I needed to read his other papers to get an insight into his thoughts. I began a considered effort with Seven McCarthy Papers in Seven Weeks. It ended up taking about three months, rather than seven 7 weeks. Again I came back to Elephant 2000. I began to understand more as other ideas and concepts sunk in, like ascribing beliefs and goals to machines. But to really explore the ideas, I really wanted to try to implement parts of Elephant in my own programming language. The problem was, having no formal training in computer science, (my background is Physics), I had never created a programming language before. The stars aligned and I found the Instaparse Clojure library. The result is Babar, a language designed to explore communication with machines via Speech Acts.

7 McCarthy Papers in 7ish weeks #7 - Elephant 2000

Wed, 02 Jan 2013 00:30:32 +0000

Saving the best for last. Elephant 2000

To be continued….

7 McCarthy Papers in 7ish Weeks #5 & #6 - SDFW Tic-Tac-Toe

Sun, 25 Nov 2012 14:08:53 +0000

This holiday edition blog post covers two McCarthy papers instead of just one. We will be talking about Free Will - Even for Robots and the companion paper Simple Deterministic Free Will.

In which we deftly sidestep the philosophers

We know that computers and programs are completely deterministic. A philosophical question is whether we, as humans are ruled by determinism, (although complex it may be), or not. If we take the decision that humans are deterministic, then we can argue that either there is no free will - or that free will is “compatible” with determinism. Philosophers, of course, could discuss such questions interminably, trying to get a theory to fit for all people and all occasions. Thankfully, McCarthy takes a very admirable and practical view on free will. Let’s try out something simple for a computer program and see how it works. He explores a philosophy “Compatibilist’s” view, which regards a person to have free will if his actions are decided by an internal process, even if this process itself is deterministic. But by exploring this view with computer programs, he makes clear:

7 McCarthy Papers in 7ish Weeks - #4

Tue, 06 Nov 2012 13:32:04 +0000

Reading Artificial Intelligence, Logic, and Formalizing Common Sense, led me surprisingly to reflect on, not only logic and philosophy, but also the history and present state of AI.

Fist let’s look at the kind of AI that McCarthy is describing in paper. He talks of a program that can use common sense knowledge about the world around it and have this knowledge structured well enough that it can be reasoned about mathematically. In fact, he describes four levels of logic:

7 John McCarthy Papers in 7 Weeks #3

Mon, 15 Oct 2012 01:37:30 +0000

In which I realize that John McCarthy is the father of the Semantic Web

I have realized that it generally takes me more than a week to read a paper, reflect on it, experiment, and finally blog about it. But, since I made up the rules of the project in the first place, I am not going to dwell on the time frame and just move forward with the next paper.

7 John McCarthy Papers in 7 Weeks - #2

Sat, 29 Sep 2012 16:00:36 +0000

Well, life threw me for a bit of a loop and delayed my post on my second paper. So I am going to consider this a “weekish” period of time and just continue on.

I read Towards a Mathematical Science of Computation. It is quite a meaty paper and was certainly a lot to digest. Here are some highlights that I gleaned from it.

How can a Mathematical Science of Computation help in a practical way?

McCarthy points out that while it is hard to predict practical applications ahead of time. A couple of could be

7 John McCarthy Papers in 7 weeks – #1 How My Thermostat has Beliefs and Goals

Thu, 20 Sep 2012 13:03:36 +0000

Ascribing Mental Qualities to Machines or How My Thermostat has Beliefs and Goals

After reading John McCarthy’s paper this week Ascribing Mental Qualities to Machines, I can honestly say that it has changed the way I think about programs and most certainly thermostats. For you see, I realize now that my thermostat has beliefs and goals. No, it does not have beliefs about what the weather is going to be tomorrow, or when the next George R.R. Martin book is going to come out. But it does have beliefs. It has three of them to be exact:

7 John McCarthy Papers in 7 weeks - Prologue

Wed, 19 Sep 2012 01:50:08 +0000

In the spirit of Seven Languages in Seven Weeks, I have decided to embark on a quest. But instead of focusing on expanding my mindset with different programming languages, I am focusing on trying to get into the mindset of John McCarthy, father of LISP and AI, by reading and thinking about seven of his papers.

Why?

Get out of your box

If you are comfortable, you are not challenging yourself to grow. You are doomed to stay in your same mindset and your little box and your world gets smaller. As an Object Oriented programmer, I was happy in my little box. Then one day, I discovered Clojure and Functional Programming and my world became bigger and richer because of it. I hope to glean a similar box expansion, by exploring the thoughts of McCarthy. Especially, since I have the nagging suspicion that we are somehow doing programming “completely wrong.”