How You Know

People don’t pay much attention to “how” they know; they just start arguing about “what” they know. From that beginning, grades and egos and jobs are on the line. If you know the answer, you...

How You Know

Another epistemological tour de force.

Probable, Possible, my black hen,

She lays eggs in the Relative When.

She doesn’t lay eggs in the Positive Now

Because she’s unable to postulate how.

— The Space Child’s Mother Goose By Frederick Winsor

People don’t pay much attention to “how” they know; they just start arguing about “what” they know. From that beginning, grades and egos and jobs are on the line. If you know the answer, you get a better grade, you feel superior, you’re promoted. There’s security in thinking you’re building your life on a solid foundation of knowledge. The idea of “how” is disconcerting. Thinking about thinking undermines what you think. If you were looking for a cognitive rock to stand on, “how” leaves you floating.

Fortunately, knowledge is buoyant. The cognitive boat can take you to new and exciting places. With a few ideas and a handful of equations, it can fill the universe with meaning. Unfortunately, the boat doesn’t come with a warranty. The history of ideas is a record of sinkings. You can be sure (almost) of one thing: What you believe today to be certain will someday go down.

For practical purposes (for building a life or a career), the “how” doesn’t matter. The carpenter doesn’t have to know how hammers are made in order to drive nails. Nor do scientists need to know how knowledge is made in order to build theories. But then carpenters don’t claim to be building Ultimate Truth.

The “how” has two parts, roughly corresponding to “production” and “marketing”. Individuals are constantly thinking up new ideas, exploring new things and looking at old things in new ways, testing the ideas and the observations against each other, judging how much sense it all makes. Then populations of individuals “buy” some of these ideas and pass up others. The ideas that most individuals “buy” become “accepted theories” and constitute knowledge.

Hence, scientific knowledge is not an ever-closer approximation of some unknown Truth. Rather, theories are selected (in the sense used in theories of biological evolution) by the environment in which they’re proposed: by the level of awareness and understanding of the people using them, by the characteristics of that part of reality people currently live in, by the dynamics of social and cultural power. Instead of being built on a foundation, knowledge is composed of relationships.

The metaphor of construction is misleading. There is no “foundation” which justifies all subsequent knowledge built on it. Modern physics, for example, is anchored to a philosophy that sank over a century ago, as Karl Popper (among others) has pointed out. The rocks that sank it were the discoveries in the late 1800s about how the brain works. Neurons firing in your brain are distinguished only by their relationship with other neurons. Information about the world is not transmitted by nerves but is created metaphorically in the classification of impulses. Facts are not given. Evidence is not evident. And the entire apparatus (your brain) comes preassembled and running.

The construction metaphor can only go this far

The progress of knowledge is a remodeling of existing neural structures. Sequences of neural firings can be rearranged, new sequences can be added or removed. But any sequence you might think is fundamental turns out to be just another association of associations of associations. This has a couple of interesting consequences: The hegemony of physics over the other sciences is attributed to its being more “fundamental”. Presumably, the other sciences ultimately can be “reduced” to the collisions of “elementary particles” with which physics deals. Any theory in any other science, no matter how reasonable it may be in light of its own domain of evidence, must receive the imprimatur of physics to be taken seriously. The idea that psychology, say, could provide a critique of physical theories is considered absurd.

But this is what the nature of the human cognitive apparatus allows. Its mechanism of classifying neural impulses treats the evidence and theories of physics exactly the same as it does those of every other science. “Gestalts” can be the “fundamental” objects of perception as readily as can the parts that compose them. If there is a foundation to science, it’s this business of reclassification of neural relationships, not the content of any particular discipline.

Disciplines can “relate” to each other, but one can’t “dictate” to another. “Reasonableness” is the relationship of a theory to the evidence it seeks to explain, not its subservience to physics. Thus the idea that the conclusions of comparative mythology aren’t to be taken seriously until they conform to the currently accepted theory of celestial mechanics is without foundation.

The second interesting consequence concerns the many efforts to justify knowledge by starting with some simple element and building up all the rest. The brain works in just the opposite way: It starts with everything and narrows its focus to some simple thing. This has its usefulness, but along the way a lot gets discarded. When the process is reversed, what was discarded is likely to be ignored. The result is a picture of the universe that’s simplistic, reductive, incognizant.

This is what Nobel laureate Ilya Prigogine discovered in his examination of dynamics. It bothered him that the “fundamental” laws of dynamics treated time as reversible when all experience indicated it wasn’t. With the advent of the awareness of complex systems, he worked out generalized equations of state for populations of particles. He found that irreversibility of time and multiple solutions based on probability were inherent, essential characteristics of those systems. Reversibility only appeared in isolated systems at equilibrium. It’s especially interesting that the complexity of his generalized equations persists down to as few as three particles: Thus the three-body problem in gravitational analysis is already beyond the scope of traditional dynamics.

In other words, what has been proclaimed the “fundamentals” of physics upon which more complex systems are built is actually a degenerate case derived from those more general complex systems. In working up from the degenerate case to the complex, the multiple solutions are missed. To get the larger picture, you have to start with complexity and work down. The craving to justify the content of scientific knowledge, to establish it on some absolute truth, can never be satisfied. The mechanism of knowledge doesn’t work that way. This doesn’t mean our knowledge is “not true”. But its truth is a truth within limits.

It’s a truth of special cases. It’s a truth of human scale. The “how” of knowing may leave us floating, but we can learn to swim.

Mel Acheson