Saturday, March 08, 2008

What is Truth?

I used to view myself as having a pretty good grasp of reality. This picture disabused me of that.


Original Website: http://web.mit.edu/persci/people/adelson/checkershadow_illusion.html


I didn’t believe its claim that the squares marked A and B are the same shade of gray. I printed out the image. I still didn’t believe it. I cut out the A and B squares and brought them together—they match.


Below are the two squares cut out with Microsoft paint







Since my perceptions are clearly wrong with a simple image, I don’t think I should be confident that my perceptions on other things (like people) are accurate. Clearly, when senses and human frailties are involved truth can be elusive.

4 comments:

Heidi said...

But all is not lost. Truth is sought, not owned. However, truths (multiple, small t) can be built, arranged, configured, corrected, questioned.

For me, it's about navigation without ever having complete knowledge. There are reasons that we perceive the squares as different - and these have to do with all sorts of "truths" like the way our eyes work, and what we have developed to perceive and categorize what is important about visual input. The ability to understand that the perception is relative and contingent is another layer of truth, and the tools to "see" that give you more information still.

Ultimately, we cannot get the transcendent viewpoint - although I think that there are something like "tastes" of it from time to time.

So long as we can't step out of our niche, our truths are bounded by categories like space and time. They are also very relative - to "see" some things we "block others. And we carve up our realities into sets and subsets and intersecting chunks - all in ways that help us to navigate a shared space, but may have no ultimate reality.

To me that is actually a comforting thought. A chair may "really" be mostly empty space, but I'm glad that in my niche it still holds me up.

VanceH said...

Heidi, thanks for pointing out there is an alternative to existential unknowability as a conclusion. Knowing that my eyes/brain can be fooled in this way brings me closer to what is.

Scooper said...

On the other hand, your ability to perceive reality is "close enough" almost all of the time, or you would have died in some accident by now.

You can trust your perceptions. You just can't trust them absolutely. The only things I trust absolutely are God and mathematics, and both of them have allowed themselves to be misunderstood and abused.

VanceH said...

Hi Scooper,
I agree with your point.

I think it is interesting that the two things you trust absolutely are at two extremes of whether the world generally agrees or not. I suspect perceptions on mathematics are similar, whereas on God, to say that the world differs greatly is an understatement. Sensory perception would seem to fall inbetween.