International Society For Philosophers

International Society
For Philosophers

Voyages in the Possible World Machine

Geoffrey Klempner

Philosophically inquisitive robots debate the question whether human beings have consciousness.

A man is given a black box which makes infallible predictions. He believes that he can't get rid of the device because the black box predicts that he will keep it.

A hi-tech company offers whole body replacements as the ultimate insurance against injury: but what have they done with the living originals?

The Possible World Machine began as a series of talks which I gave to philosophy classes run by the Workers Educational Association in Sheffield in 1991–2.[1] Later, much expanded, the collection of science fiction stories and philosophical dialogues became the first of the six Pathways to Philosophy.[2] The first intrepid distance learning students climbed aboard in 1995.

As a teenager, I devoured science fiction. My heroes were Philip K. Dick, Ursula Le Guin, Frederick Pohl, Isaac Asimov. When, many years later, I turned to the study of philosophy I realized what it was that had gripped me about those tales of fantastic worlds. Not alien invaders, space ships and bug-eyed monsters, but ideas pure and simple.

As critics have pointed out, the Time Machine of H.G. Wells is beset by paradoxes.[3] At least we know — or think we know — what it would be like to go for a ride in a time machine. But what could be the purpose of a possible world machine? Using our minds to think about how things might have been in another possible world is all it takes to be there. It is not empirical, factual inquiry but imagination — tempered by logic — which tells us what might, or might not have been the case in some possible world.

That is the main point of the eponymously entitled first story in Pathways Possible World Machine. A story or novel does not merely describe what you would see if you travelled in a possible world machine. It is a possible world machine. So is a thought experiment which the philosopher uses to test a concept or a theory — including theories about the nature of time or possible worlds.

One of the arguments which I've debated with my students is if you travelled to a possible world it wouldn't be a possible world, it would be actual. If your existence is an actual fact, then any place that you visit must be actual too. Possible worlds are worlds that might have been, not worlds that are. So, logically, words or pictures are the only vehicle that one can use to reach a possible world.

For the Pathways Introduction to Philosophy program, the fifteen short stories with introductions are supplemented by thirty philosophical dialogues. These are more demanding, in some cases invoking recent debates amongst philosophers. Many of the exchanges derive originally from classroom discussions which have stuck in my memory, or arguments with friends and colleagues. As one would expect, there are no definite conclusions only more questions.

In 2003, units from Possible World Machine, supplemented by units from some of the other Pathways programs were used as the basis for a course for students at Catherine McAuley Catholic Girls High School, Sydney. The ages of the girls ranged from 14-16. As the course director Matthew Del Nevo writes:

The virtue of Pathways Schools for practitioners of the Community of Inquiry pedagogy — as promoted by SAPERE in England — is that it gives a structure and framework, a directedness, to the proceedings. The Community of Inquiry is not ad hoc, but arises out of common reading, comparable research and common written assessment at the month's end. This makes for an improved Community of Inquiry.[4]

That is one approach, which requires that teachers have a confident grasp of the Community of Inquiry methodology. I have tried this myself with my WEA students. I found it rewarding but also very exacting. It is important from the start that the students fully buy in to the idea of a community of inquiry. For seasoned adult learners who are used to sitting back and being lectured to, that can sometimes be more difficult than for school students.

There are alternative approaches which can be used in the classroom. For example, I would like to see students encouraged to write their own dialogues and short stories, using Possible World Machine as a template or inspiration from which to create their own original material. Some of the best pieces of work I have received from my Pathways students have taken this format.

Philosophy is much more than analysis and critical thinking. It is thinking creatively about questions that are often difficult to pin down, problems which require the capacity for vision as well as logic. In philosophy, it can be a major achievement just being able to state what it is that troubles or grips you. Indeed, philosophy is the only subject that I know of where vision and logic are equally important. That's what makes it such a great subject for stimulating the minds of young people.

It seems to me that one of the unfortunate side-effects of the current push towards imparting skills that are seen as valuable in the market place is the one-sided emphasis on critical thinking. The ability to question assumptions and think clearly is vital. But in order to solve the problems that face us we also need to be able to come up with new ideas, and not just novel combinations of the old. We need people who dare to think differently.[5]


1. 'Can Philosophy be Taught?'

2. Program A. Introduction to Philosophy

3. See my 'Afterword to The Man Who Folded Himself'

4. 'Pathways Schools 2003' by Matthew Del Nevo and Peter Schmiedgen

5. In addition to the fifteen science fiction stories with introductions from Possible World Machine which can be downloaded free from the Pathways web site, I have prepared two texts exclusively for use in schools. The first text, Possible World Machine consists of the complete set of dialogues from the Pathways Introduction to Philosophy program. The second text, Pathways Schools consists of units taken from the Ancient Philosophy, Philosophy of Mind, Moral Philosophy and Introduction to Philosophy programs. See:

Pathways Downloads

© Geoffrey Klempner 2002–2017


[This article first appeared in the SAPERE Communities of Enquiry Newsletter for September 2007]