News > September 18, 2008

By Grace Beehler | Contributing writer

During his philosophy lecture on Sept. 11, Dr. Fred Dretske claimed that our experiences are actually exponentially more vibrant and textured than what we consciously recall.

Dretske, 76, joined Duke University as a Senior Research Scholar in 1999 after retiring from Stanford University. Dretske began his career as a professor at the University of Wisconsin-Madison. An epistemologist and philosopher of the mind, he focuses his research on the conscious experience and self-knowledge.

Dretske was awarded the Jean Nicod Prize in 1994 for his lecture “Naturalizing the Mind.” This esteemed prize is awarded annually to a leading cognitive scientist or philosopher of the mind.

In his talk with the university’s philosophy department, “What We See: The Texture of Conscious Experience,” Dretske attempted to debunk the belief that we cannot access all the details that are really in the environment.

Dretske claims that there is a difference between perceiving something and actually seeing it. The visual perception of X is unconscious; whereas seeing X is the perception of X when it is embodied in a conscious experience.

He begins by defining several terms. Objects, Dretske said, could be a box, tree, goose or even an event such as a wedding. He goes on to define properties, which are colors, sizes or positioning. Facts, he said, are what we come to know by seeing objects and properties.

With the more objects one sees, the texture of the experience is greater.

Dretske refutes three fallacies. The first is that one cannot be sure of what he is seeing because he could be experiencing deceptions and therefore he would not see the facts. However, the subject confuses seeing facts with seeing objects. The second fallacy is that people cannot see color in their extreme peripheral vision and therefore they cannot see the object. In actuality, the subject confuses seeing objects with seeing properties.

The third fallacy is that the subject confuses seeing objects with seeing facts.

With these fallacies cleverly avoided, the question then becomes, “can you have knowledge without belief or thought?” The answer to this, Dretske believes, is yes. We have knowledge of things because we retain information, even if it is unconscious. It just takes a little bit of prodding to recall. This is labeled as tacit knowledge.

Another aspect of tacit knowledge is change blindness. This is when a subject is shown an image and then quickly shown another seemingly identical image and fails to notice a significant change. What Dretske claims is that one visually perceives the change but fails to recognize it because he is focused on a separate aspect of the scene.

“Sometimes you know things you don’t know you know,” Dretske said.

Basically, we can know certain facts about a part of a whole because we know facts about the whole. For example, you see a flock of geese flying south for the winter. You cannot see the individual goose because it is too high, but you can tell that the individual is flying south.

These concepts are applicable to daily life, not just philosophers. Sophomore Hope Nardini began to question what is really reliable, especially in eye-witness testimonies. “You can perceive it but not recognize it,” She said. Maybe if people slow down and take more time to recall information, hundreds of cases could be solved.