Page 1 of 1

Lewis on Axioms/Presuppositions

PostPosted: 04 Jan 2010, 12:04
by sqrt[-1]
Did CSLewis ever write anything on Axioms or Presuppositions?

I am not even sure that is the correct terms - I am thinking along the lines of ideas that form the "root" of your thinking that you use to build your ideas/beliefs upon. (eg. "The laws of logic are true", "I exist", "I experience the world in it's real form" etc)

Re: Lewis on Axioms/Presuppositions

PostPosted: 04 Jan 2010, 13:08
by archenland_knight
Greetings i:

I don't think we've met before.

I suppose that in a way, "The Abolition of Man" deals with the subject, but I'm not sure if it's the sort of approach you're thinking of.

Re: Lewis on Axioms/Presuppositions

PostPosted: 06 Jan 2010, 12:04
by sqrt[-1]
Hi,

I can't say that I remember much about the themes in "The Abolition of Man" - I will give it a re-read and let you know.

What I was looking for was similar to axioms in mathematics - except for philosophy. eg. In maths everything is derived from a set of laws (called axioms) which are just assumed to be true.
http://en.wikipedia.org/wiki/Axiom

I believe that in philosophy there may exist a similar set of root beliefs that a person may have (possibly Presuppositions?) and was wondering if Lewis wrote anything on the topic. (purely for my own interest)

Thanks again.

Re: Lewis on Axioms/Presuppositions

PostPosted: 11 Jan 2010, 23:14
by archenland_knight
i wrote:In maths everything is derived from a set of laws (called axioms) which are just assumed to be true.


I think it would be more accurate to say that axioms (or "postulates") are "statements which seem self-evident but which cannot be proven". They become the starting point for mathematical proofs, but with the clear acknowledgement that should one of them be disproven, all proof using the disproven axiom will become invalid.

An example would be, "For any give point A and point B, where A and B are not the same point, there exists between then another point, C." This, then, can be used to "prove" that between any two points, there exists an infinite number of points.

Not all axioms are universally assume to be true. Euclid's parallel postulate is the most common example of an "axiom" that is not universally assumed to be true. It is a postulate of great consequence. Much of our engineering relies on theorems proved using this postulate.

For instance, everyone "knows" that the sum of all the angles in a triangle is exactly 180. However, no one has ever managed to prove this without Euclid's PP.

Thus, there are two basic types of geometry. "Euclidean" geometry uses Euclid's PP as a postulate. "Non-Euclidean" geometry basically says, "Okay, let's propose alternatives to Euclid's postulates, and see what we get."

In fact, Einstein's "General Relativity" works much better in non-Euclidean systems because when you start talking about "curvature of space", Euclid's systems get thrown all out of whack.

The Wikki articles on Euclidean geometry and Non-Euclidean geometry explain it pretty well. And I can only remember so much from my Non-Euclidean geometry class 20 years ago.


Oh ... I have no idea if Lewis may have addressed this concept more specifically than what I read in "Abolition of Man".

Re: Lewis on Axioms/Presuppositions

PostPosted: 02 Mar 2010, 20:34
by Nerd42
Yeah The Abolition of Man deals with axioms in philosophy of ethics. Lewis was very critical of evidentialism and I recall him making the "infinite regress argument" against it at some point though I don't at present remember where.