In an earlier post, I wrote “a proper understanding of direct perception actually tends to undermine both traditional epistemology and traditional philosophy of mind.” Today, I want to expand on that.
Both traditional epistemology and traditional philosophy of mind assume that humans are rational agents. So let’s take a look at what is a rational agent.
Rational agents
An account of the basic ideas of rational agency can be found in the Wikipedia entry, or in the Stanford encyclopedia.
The basic idea is that perception presents the state of the world to a rational agent. The agent then uses logic in order to decide which actions will best meet the agent’s desires. If the logic is too complex (or computationally intractable), the agent might instead use an heuristic which approximates what should be the result of that logical deduction.
It is, in short, an input/output model. The agent receives input, and computes appropriate actions (outputs). This kind of input/output model fits the way that we use computers, and is the basis for a lot of research on Artificial Intelligence. This input/output model is also behind the commonly expressed view that the brain is a computer.
It is part of the typical rational agency view, that perception is passive. The general view is that sensory cells pick up signals from the world (or the environment), and determine everything important from those passively received signals. In the view of many, the inputs themselves are meaningless as received, and any meaning is added by the computation that the brain does on the passively received inputs.
Active perception
It is part of the view of the proponents of direct perception, that perception is active, not passive. We are part of the world, and as such we continuously interact with the world. We are not outsiders looking on. Gibson points to the motion of the eyes in saccades, as evidence of our active engagement in the perceptual process. This emphasis on our interaction with the world is sometimes called interactionism or embodied cognition.
Gibson describes his account of perception as an ecological theory. The name reflects the interactive nature of perception. He says that we perceive affordances, where an affordance is something that affords us or offers us an opportunity. A mail box affords us the possibility of being able to mail a letter. Food affords us the opportunity of obtaining nourishment. I prefer to express that by saying that we perceive opportunities – the word “opportunity” is less confusing than the word “affordance.”
For me, the idea that we perceive opportunities comes from the assumption that we are the products of biological evolution. It seems implausible that evolutionary processes would result in something like the rational agent of a Platonic ideal. Rather, evolutionary processes should be successful to the extent that they produce organisms or agents that are able to meet their biological needs. So this evolutionary approach suggests that perceptual systems should have evolved to identify opportunities to succeed. For this, the term “opportunistic agent” seems to be a better fit than “rational agent.”
If I do a google search for “opportunistic agent”, I find references to such things as weeds or disease causing microbes and parasites. The idea of biological systems being opportunistic is well understood. As biological organisms ourselves, it makes sense that we too should be opportunistic.
The term “opportunism” is often seen as a negative, perhaps suggesting an amoral greed. However, there is no reason that it cannot also be seen in a more positive light, a seeking of moral opportunities or opportunities to help our fellow citizens as members of a social group.
If perception seeks opportunities, as suggested, then what we perceive is already meaningful to us, by virtue of it satisfying our needs. So we at least have a beginning of a way of understanding where meaning originates.
Perceptual learning
If what we perceive are opportunities, then part of learning is in learning what are the environmental indicators of opportunities. This is perceptual learning. On Gibson’s account, we build transducers to recognize particular types of opportunity. So a great deal of our learning is in the form of perceptual learning.
I remember, in my early teens, going with a group (mainly adults) on a kangaroo hunt near Busselton, Western Australia. One of the participants pointed, and said “there’s one.” I looked in the direction that he was pointing, but I did not see a thing. It turned out that the kangaroo was partially hidden in the bushes. Shortly thereafter, somebody aimed, and shot himself a kangaroo. From that experience, I learned that how to see kangaroos (or other game) is something that we have to learn. How to properly see what is under a microscope is another example of having to learn. These are examples of perceptual learning, of tuning our perceptual systems to be able to pick up the kind of information that we are seeking to present us with opportunities.
One of the things that a child must learn, is how to cross safely cross the street. Presumably, the “rational agent” view of this would be that the child must absorb many rules of safe crossing, and then use logic to apply those rules to the current situation. The “opportunist agent” view is that the child learns to recognize opportunities to safely cross the street, and to choose such an opportunity to cross.
Epistemology
Typically, “epistemology” is said to be a theory of knowledge. And it is often said that knowledge consists of justified true beliefs. If we receive neutral data from the world, and what we know of the world comes from applying logic to that neutral data, it makes sense to say that knowledge is in the form of beliefs.
From the perspective of direct perception, that is not how we come to know the world. Rather, much of our learning is in the form of perceptual learning, or of tuning up the perceptual system to recognize opportunities that are available to us. Thus we should see knowledge as residing in that perceptual ability, as resulting from that perceptual learning.
This suggests that knowledge and belief complement one another. Knowledge provides us with the abilities to recognize opportunities, and then beliefs are the information on specific opportunities that have been recognized.
One of the problems of epistemology, is that of underdetermination, sometimes called “the poverty of stimulus problem.” If our only access to the world is via a finite set of observed facts, then there are infinitely many possible worlds that could fit those facts. So how could we possibly be able to tell what the world is like? This is a limitation of the idea that perception is passive, so that we only have access to data received from the world. If perception is active, as direct perception proposes, then we have both data from the world (or beliefs), and the learned methods by which we acquire that data (our knowledge). Having available the method of acquiring meaningful data, in addition to the data itself, tells us far more about the world than would just the data. This takes us in the direction of solving the underdetermination problem.
Summary
I have described some of the ways that direct perception gives us a picture of our relation to the world that is very different from what is presented by traditional philosophy.
The Heretical Philosopher 