Expert: J.M.J. West - 4/6/2009

Question
Hello. How does one prove rationally and scientifically that objective reality
exists or not? How do we know if what we experience is objective reality? If I was
just born yesterday and I see pink elephants how do I know if its truth or
fantasy?

Answer
Joe,

Great question (one of the fundamental questions of modern philosophy); and one which by most all accounts modern philosophy has not been able to answer satisfactorily.

Being born yesterday, you'd have no reference for pink elephants.  Being born over a dozen years ago, you've encountered many elephants, all of whom were a grayish brown color, and from this fact you've used induction to thereby posit that "all elephants are brownish-gray", but this is in fact an unjustifiable claim unless you've knowingly seen all elephants that ever were, are, or will be, and they've all been the same color.

Most modern philosophy begins with the fact of empiricism, which states that the primary building blocks we have for knowing about the world are our sensory perceptions.  Starting from the fact that "i am having a perception of greenness and brownness" I cannot, logically, ever arrive at the conclusion that I am actually perceiving a tree which is existent and external to myself.

This makes for some very bar-room or coffee-table discussions about what is real, culminating for many in the Matrix movies or some view of the world radically similar in scope, because if we begin from sensory perception, we cannot ever "gain" the external world.

But to anyone who adheres firmly to this belief, I dare him to get the sensory perception of a bus speeding towards him without stepping out of the way...they won't do it, because we all KNOW that the world exists.  This gives us one of the fundamental flaws of empiricism, which has shaped the direction of much of modern philosophy, especially modern Anglo-American philosophy.

Ironically the very metaphysics which the Modern Philosophic Project was trying to replace - Aristotelianism (most poignently found in  Thomism) - is the only philosophical structure capable of making belief in the external world reasonable.  

It does not begin from sensory perception (which was itself a knee-jerk reaction to Descartes 'Cogito' ("I think, therefore I am"), which tried to get rid of everything about which we were not certain, but but left Descartes stuck in his head), but rather from the fact that our sensory impressions are distinct from all other mental content precisely because they are caused by external objects acting on us.  It begins with the common-sense fact that the world exists; which is not to be jettisoned merely because of a word-puzzle.

Hope that helps.

For a more in depth reading of the only possible answer to this question, you might dig this book:
The One and The Many, by Norris (not Chuck) - get it at amazon:
http://www.amazon.com/gp/product/0268037078?ie=UTF8&tag=gotjus-20&linkCode=as2&c...

Peace,

-J.M.J. West