(as adapted from Richard van de Lagemaat, Theory of Knowledge for the IB Diploma)
“It’s not what you look at that matters, it’s what you see” – Henry David Thoreau
“Two-thirds of what we see is behind our eyes” – Chinese proverb
“Things do not seem the same to those who love and those who hate, nor to those who are angry and those who are calm” – Aristotle
“You can’t depend on eyes when your imagination is out of focus” – Mark Twain
“If the doors of perception were cleansed, everything would appear to man as it is – inifinite” – William Blake
THE ARTS– To what extent to the arts help us to see the world with new eyes?
ETHICS – Do “good” people see the world differently from “bad” people?
HISTORY – Should we trust eye-witness accounts?
HUMAN SCIENCES– How does the act of observation influence what is observed?
EMOTION – How does your mood affect your perception of things?
NATURAL SCIENCES– How far do expectations influence observations?
LANGUAGE– How does the way we describe something affect the way we see it?
REASON – Which is a more reliable source of knowledge – perception or reason?
What is Perception?
Perception = the awareness of things through our 5 senses, or the “gates and windows” of the mind, the channels of communication between ourselves and the outside world.
5 senses = sight, sound, touch, taste, smell
If you had to sacrifice ONE of your senses, which would you be most willing to lose and which least willing to lose?
MOST people answer that they’d least be willing to lose sight, and most willing to lose smell. Smell is sometimes referred to as the “mute sense”. Think about it – we have thousands of terms for colors but not much other than “smells good/bad”. In reality, we can distinguish more than 10,000 distinct odours. Moreover, smells can trigger powerful emotional responses in the brain, as this sense has a more direct route than then other four.
What is Empiricism?
Empiricism is a major school of philosophy that states ALL knowledge is ultimately based on perceptual experience, and that, in essence, one cannot be born with knowledge or obtain it without perceiving it. Some famous empiricists are David Hume, George Berkeley (UC Berkeley named after him), John Locke, and to some extent, Leonardo da Vinci, who said “All our knowledge has its roots in our perceptions”
Caution- some adult language in the above vids!
What is Common-Sense Realism?
This suggests that perception is passive and straightforward – that our senses are more or less reliable and give us an accurate picture of the world…HOWEVER, we all know that our senses can fool us sometimes, and that our experience of the world is affected by our unique sense organs and minds as well.
What are the 2 Main Factors in Perception?
Sensation– which is provided by the world
Interpretation – which is provided by our minds
***First have fun with the BBC challenge
VISUAL ILLUSIONS can illustrate how these 2 factors come into play. Keep in mind the following:
CONTEXT: the way we see something depends partly on the context in which we see it. For example, we understand perspective so seeing a larger figure in the foreground does not necessarily mean it is in reality larger than the figure in the background, which is further away.
FIGURE AND GROUND: When we look at something we tend to highlight certain aspects of what we see (“figure”) and treat other parts as background (“ground”)
VISUAL GROUPING: We have a tendancy to look for meaning in what we see and group our perceptual understanding into shapes and patterns. Even with little sensory information, we can construct meaning out of an object by “filling in” the gaps.
How long did it take you to figure out what is in the image above?
Collection of Categorized Illusions
Spanish Castle Illusion
Dragon Illusion (with video)
The Stroop Effect
94 Optical Illusions
Why is it so hard to proof-read a paper for typos? Our expectations definitely play a huge role in how we see things.
More WORD ILLUSIONS
Our mind (our unconscious) does a great job of making sense of what we take in with our senses. Consider this- your image in the bathroom mirror is actually about half the size of your head- but when you’re checking yourself out you never think you’ve shrunk – it always appears to be the right size.
Unfortunately, some people suffer from a condition called visual agnosia, in which their damaged brain makes them lose the ability to interpret what they see.
Here is a great story by Hilary Lawson on that experience
One reason for being cautious about what are senses tell us is that perception is by nature selective. Our minds have to pick and choose what to notice since there is a constant deluge of sensory information coming at us at all times. Like a figure/ground illusion, certain aspects of all situations “Stand out” and others fade into the background.
What makes things “stand out”? One is INTENSITY– something strong or loud, pungent or colorful, for example. The other is CONTRAST– like that coffee spill on your white tee shirt! Another is MOVEMENT – evolutionary speaking, we need to be startled by movement in order to protect ourselves.
But of course there are other factors that play in – such as personal interest and mood. Photographers are really great at captalizing on what catches their eye as aesthetically pleasing or able to tell a story.
How would a TREE be seen by: a: a logger b: an environmentalist c: a biologist d: a native American ?
When our interests shift, so do our perceptions, which explains the phenomena that pregnant women suddenly notice scores of other pregnant women wherever she goes.
Mood explains the glass half full/glass half empty differences between optimists and pessimists. When you begin a romantic relationship, you notice everything you have in common; when it dissolves, you point out all the things that made you different and incompatible. The “Fear Factor” greatly alters our perceptions, which is why after telling ghost stories around a camp fire even the rustle of leaves scares the pants off you!
Finally CULTURE can affect our perceptions – how does it affect yours?
It can be said that we often see only what we want to see – how do your beliefs affect the way you see things?
Imagine you’ve witnessed a violent crime and get a brief but clear glimpse of the assailant. What confidence would you have that you could correctly identify one of the following men?
Eye-witness accounts have traditionally been trusted, but recent DNA tests have proved that they are not infallible. The eye is not a camera – everytime we “remember” something, we actually reconstruct it.
Think back to an early childhood memory. Are you sure about the SOURCE of this memory? Do you recall experiencing it, or did your parents tell you so many stories about it you think you remember it?
Even though we might misremember, misinterpret, or fail to notice something, it would be impractical to be overly skeptic about everthing we take in through our senses.
How can we effectively distinguish between appearance and reality?
1. Confirmation by another sense – does it look like and apple AND taste like one? Can you see the wall AND bang your head against it?
2. Coherence – does it “fit in” with your overall experience of the world?
3. Independent Testimony – what do other people say? do they “confirm” your perceptions?
IS THERE AN “ULTIMATE REALITY”?
1. PAIN/ TASTE/ COLOR
Galieo once quipped: “The tickle is not in the feather”. If you burned your hand on the stove, you know enough about biology to agree that the pain is in your hand, not some thing in the stove coils independent of your experience with it. If you drink a soda it tastes sweet – does the sweetness exist in the soda itself, or only in your mouth? Is the “Sweetness” a subjective experience resulting form the interaction of your taste buds and your mouth.
But what about things like colors? Surely snow is white(ish) and grass is green. BUT if we apply the same reasoning as the soda/stove then the green is no more in the grass as the sweetness was in the soda. So….the “green-ness” is merely a result of the ways our eyes are sensitive to light wavelengths and the physical structure of the grass. Does this mean, in effect, the world is colorless?
2. TREE IN THE FOREST
You’ve probably heard the well-known saying “If a tree falls in the forest and there’s no one there to hear it does it make a sound?” If you think that the sound of a tree falling is nothing more than the effect of air vibrations on our ears, and if there were no ears in the region, then the tree does NOT make a sound. But can we make a distinction between the kinds of “sound”?
Physical Sound = vibrations in the air caused by things like falling trees
Experienced Sound = the actual crash or whatever we hear when trees hit the ground
Given these definitions, we can say in our puzzle that there IS “Sound #1” but NO “Sound #2”
Does this mean that in the early days of Earth’s formation the planet was silent, or if we removed all ears and other hearing devices from all creatures our planet would again be totally hush? Extending that to color…if no one had eyes or the ability to see would roses not be red and grass not green (at least in the “experiential” sense)?
This reasoning leads us to wonder whether anything can be said to exist independent of our experience of it.
3. TABLES IN THE CLASSROOM
After everyone leaves campus for the day, how do you know the tables/ desks are still in the classroom? It’s like “How do you know the light goes off when you close the firdge door?”
Perhaps tables on behave when someone is watching them, but as soon as no one’s around they dance around and create havoc. Even if you filmed the room you could still ask: “how do you know the images of the obviously static tables stay on the film when you are not watching it?”
Perhaps right now you might be skeptical of philosophers who ponder these seemingly inane questions and are saying to yourself WHO REALLY CARES??!! Perhaps you are thinking we shouldn’t worry about what tables do on their own time…all that matters is how they act when we’re around.
THEORIES OF REALITY
There are 3 major theories about the relationship between perception and reality:
1. COMMON SENSE REALISM (Slogan: What you see is what is there)
The way we perceive the world basically mirrors the way the world really is. BUT…since we’ve explored how what we perceive is determined (at least in part) by our own unique sense organs, there migth be some good reasons for rejecting this theory
2. SCIENTIFIC REALISM (Slogan: Atoms in the Void!)
The world exists as an independent reality, but is very different from the way we perceive it. Just think about all the electric charges, atoms and other miniscule moving parts that comprise a seemingly static, solid object like a chair. According to this theory, the wolrd is a colorless, soundless, odourless realm of atoms whizzing around in space.
***most scientists are intuitive realists and believe they are making discoveries about an existing independent reality.
3. PHENOMENALISM (Slogan: To be is to be perceived)
This is radical empiricism (all knowledge is based on experience). Phenomenalism says that matter is simply the permanent possibility of sensation, and the world is not independent of our experience of it. I bet you can think of some Hollywood movies that use this philosophy. It emphasizes we see the world from a human perspective and shouldn’t really be philosophizing about the nature of reality!
Some Perception plots in films:
Chinatown; Donnie Darko; Memento; The Truman Show; Fight Club; Inception; The Matrix; Vanilla Sky; Mulholland Drive; Shutter Island; The Sixth Sense; Eternal Sunshine of the Spotless Mind; The Crying Game; The Manchurian Candidate; Pleasantville; The Machinist; Brazil
Practically speaking, it probably only makes sense (no pun intended) to doubt our senses only if there are good reasons for doing so – after all, evolutionarily speaking they got us this far. And if knowledge is defined as something a bit less than certainty, that works! ***If the perceptual evidence is consistent with other Ways of Knowing, such as Reason and Intuition, then it is probably a reliable source of Knowledge.
BellaDonna Effect (with Video)
Escher-esque impossible drawings
Shifting Objects Illusion
Now you see it – now you don’t (with video)
A New Kind of Color Blind (with video)
Checkerboard Illusion and the Munker-White Illusion
Sillhouette Illusion (with video)
1. Read this entire post thoroughly and explore all the links
2. CURATE an optical illusion (or more than 1) you find particularly interesting and post to your blog so we can share them. If you can explain how it works that would be great.
3. Choose 1 sense (sight, hearing, taste, touch, smell). CHoose 1 hour of your day and keep track of absolutely EVERYTHING you experience through that sense ONLY and record it on your blog.
4. Respond with a paragraph regarding your reading of Hilary Lawson’s story about visual agnosia
5. Which of the 3 “Theories of Reality” do you most adhere to? Explain.
6. We are all very good at seeing only what we want to see. Can you give some examples of the way in which our BELIEFS, CULTURE, or MOOD affects the way we see things?
7. CURATE and article or video regarding ANY of the senses and sene perception. Try to find at least 2 knoweldge issues and post all to blog