John McCarthy was known to many of us in the Artificial Intelligence community as the "Father of AI", and I came to know him as very much a baby in the subject. In my student days in the early 1970s he appeared on the BBC TV program "Controversy" in debate with Sir James Lighthill on the value of research on general purpose robots alongside my PhD supervisor, Donald Michie, himself an AI pioneer and war time code breaker who had worked with Alan Turing at Bletchley Park.  He wrote and communicated widely on his interests in robot decision making.

Typical of John's desire to communicate about his field was a short sci-fi story he wrote in 2001, "The Robot and the Baby" which has many interesting themes, and to me epitomises his breadth of interests, politics and fascinating opinions.  A capable companion robot – “Robot Model number GenRob337L3, serial number 337942781--R781 for short” – was one of many deployed to assist people and deliberately made unappealing and emasculated by the constraints society had placed on robot use.

The story begins:

“Mistress, your baby is doing poorly. He needs your attention.”
“Stop bothering me, you …''  …  “Love the … baby, yourself.”

John amusingly includes a long line of reasoning by R781 in the bracketed notation of LISP on probabilities of the baby being harmed if it disobeys its key constraints:

(= (Command 337) (Love Travis))
(True (Not (Executable (Command 337))) (Reason (Impossible-for robot (Action Love))))
(Will-cause (Not (Believes Travis) (Loved Travis)) (Die Travis))
(= (Value (Die Travis)) -0.883)
(Will-cause (Believes Travis (Loves R781 Travis) (Not (Die Travis))))
…

With this reasoning R781 decided that the value of simulating loving Travis and thereby saving its life was greater by 0.002 than the value of obeying the directive to not simulate a person. There follows a progressively escalating series of events where the whole world is watching the handling of the situation by the authorities, and commenting in real time on the event on social media - anticipating Twitter by some years.

Read the story (at http://www-formal.stanford.edu/jmc/robotandbaby.html) if you want to explore an informed opinion on the ethics, issues and dilemmas involved in human and robot interaction, which one day we may face. The story has many thought provoking elements. I personally feel for the emasculated robot that is left in the Smithsonian.

• http://news.stanford.edu/news/2011/october/john-mccarthy-obit-102511.html
• http://www.guardian.co.uk/technology/2011/oct/25/john-mccarthy

John was an early pioneer of AI, inventor of Lisp, and indeed originator of the term "AI" in 1956. See http://en.wikipedia.org/wiki/John_McCarthy_(computer_scientist). It is good to see how broad and expansive John McCarthy's vision for computing was:

From Wikipedia: In 1961, he was the first to publicly suggest (in a speech given to celebrate MIT's centennial) that computer time-sharing technology might lead to a future in which computing power and even specific applications could be sold through the utility business model (like water or electricity).

Take a look also at his short sci-fi story "The Robot and the Baby" for some great fiction (or is it?) about future robotics. See

• http://www-formal.stanford.edu/jmc/robotandbaby/robotandbaby.html

I worked with John both before and after his formal retirement, and it was a very enjoyable experience. His interest in formalising the notion of "context" was his most recent work which I spoke to him about. The ability to "assert that the proposition p is true in the context c" is a key to much of what we do in planning... and my own work some 30 years ago was involved with something I called "functions in context" that had similar aims.