Contingency and Constraint Propagation

To have an intelligent conversation about what should be done in the present to prepare for a better future, a number of basic concepts should be understood. Two of these basic concepts are “contingency” and “constraint propagation.”

What does “contingency” mean in philosophy?

In philosophy and logic, contingency is the status of propositions that are neither true under every possible valuation (i.e. tautologies) nor false under every possible valuation (i.e. contradictions). A contingent proposition is neither necessarily true nor necessarily false. Propositions that are contingent may be so because they contain logical connectives which, along with the truth value of any of its atomic parts, determine the truth value of the proposition. This is to say that the truth value of the proposition is contingent upon the truth values of the sentences which comprise it. Contingent propositions depend on the facts, whereas analytic propositions are true without regard to any facts about which they speak. __ Wikipedia Philosophical Contingency

The concept of contingency is related to the idea of “constraint” and “constraint propagation.” We can help to clarify the connectedness of the concepts by looking at the definition of “constraint:”


[ kənˈstrānt ]

noun: constraint · plural noun: constraints
a limitation or restriction:
“the availability of water is the main constraint on food production”

synonyms: restriction · limitation · curb · check · restraint · control ·

    • stiffness of manner and inhibition in relations between people:
      “they would be able to talk without constraint”

      synonyms: inhibition · uneasiness · embarrassment · restraint ·

Constraint propagation is often used in artificial intelligence work, but we will limit our discussion of constraint propagation to cognitive psychology and light philosophy.

The assignment of meaning to one part of the scene limits the possible interpretations of other parts of the scene… Constraints “propagate” or spread because, once you have limited the possible interpretation of one part of the scene, that limits or constrains the possible interpretation of other parts of the scene. Eventually the process converges on a single set of interpretations of all the lines and vertexes in the scene. At that point, the scene is understood.

Our first example involves a famous visual illusion, an ambiguous figure called the Necker Cube. It is one of the oldest visual illusions studied by psychologists, dating from the 1820s. The line drawing of a cube can be interpreted more than one way. Psychologists call this an ambiguous or bi-stable figure.

The Necker Cube

The Necker Cube appears to change its orientation in space as you stare at it. This happens because the stimulus can be interpreted in two ways that are equally good or “legal.” Cognitive scientists interpret this as “competing high-level perceptual representations being activated in response to a given visual stimulus” (Suzuki and Peterson, 2000).

To use the language of constraint satisfaction, there are two interpretations of the cube that satisfy all the constraints of the sensory input, so the brain alternates between two equally acceptable interpretations.

What sort of “competition” takes place?

If you don’t see the two different configurations, just stare at the cube for a while. It will change. If you do see the two different interpretations, experiment with holding the cube in one configuration, resisting the competition from the other interpretation. Suzuki and Peterson (2000) found substantial effects on this task from intention, which is what most people call willpower. However, eventually the neurons representing one option will fatigue, and the other option takes over (the cube flips).

Either A or B appears closer.

The Necker Cube has eight vertices. Of these eight, six are arrows around the edges, two are forks in the middle. The forks, A and B, determine the viewer’s interpretation of the Necker Cube. If you interpret A as closer to you than B, then A is a “downward pointing outer corner.” A marble placed on top of the cube (if the cube was solid) would roll toward you, hence it is a downward corner. If you interpret point A this way, then point B must be an upward pointing inner corner.

This is what is meant by constraint propagation [in cognitive psychology]. The interpretation of one element “spreads its influence” or propagates to adjacent elements. Now, when your neurons get tired of one interpretation, so (for example) they start interpreting point B as an upward-pointing outer corner, that forces your brain to re-interpret point A at the same moment. So the cube flips as a whole. The cube is treated as a gestalt, a whole thing, and the interpretation of each line and vertex must be consistent with the interpretation of the whole.

__Constraint Propagation in Cognitive Psychology

This concept is powerfully dynamic, and underlies a great deal of our perceptual interpretations as well as our conceptual thinking. Understanding how networks of neurons (and networks of networks of neurons) work automatically to propagate systems of constraints throughout our brains is an early step toward understanding the rapid automaticity of massively parallel neuronal “computing.”

You can also think of contraint propagation as the orderly collapse of an array of standing dominoes, or the dynamic patterns of Conway’s Game of Life.

In everyday life and folk psychology, we can think of constraint propagation in terms of “imposed limits which enhance functionality.”

Picture a small pile of metal. A machinist shapes it up and voila you’ve got, let’s say, a lock and key. It’s great. It’s got function. It serves your purposes. Much more so than a small pile of metal. So what did you add that made it functional?

Oxford professor Michael Polanyi says nothing was added. What makes it functional is not an addition but a subtraction. A pile of metal can take all sorts of forms. You can pile it this way; you can pile it that way. Locks and keys are highly constrained. Machinists make the parts with what they call “low tolerances” meaning a lot of constraint and specificity on their shapes and sizes so that the parts interact with each other just so.

As a result, the lock and key do fewer things, not more than the pile did. When the lock and key get old and worn out, they lose function, but, Polanyi points out, they do so by gaining more possibilities, more configurations of the parts or technically, more “degrees of freedom.” In other words the parts get looser than they were. Now the old clunker can jam or the key flops around.

A broken machine does more things, not less. We prefer our machines highly constrained. __ Ambigamy Insights

We might look at contingencies as conditional constraints, and constraints as active explicators of contingencies.

Put simply, whenever one thing is changed, several other things are likely to be changed at the same time — often in an unpredictable fashion. This is something that most persons in government and various policy-making organisations generally fail to take into account.

Human beings are fairly simple and transparent in their hopes, aspirations, dreams, and goals. Grifters inside government, academia, media, advertising, doomer-cults, political movements, organised crime, labour unions, and other disreputable associations take advantage of this simplicity-of-mind to create dependencies, addictions, and deep indebtedness. All of these things seriously constrain individual humans, and the human future in general. More: Bruce Charlton’s online book “Addicted to Distraction”

These irrational, self-imposed and other-imposed constraints propagate throughout societies and global human populations. Degrees of freedom for humans become severely curtailed, and many potentially glorious human futures fall away, unrealised.

These, and many other basic ideas inform some of the Al Fin themes, such as “The Next Level,” and “The Dangerous Child.” In the opinion of Al Fin Futurists, a desirable future such as is envisioned in The Next Level theme is tightly constrained by most governmental and non-governmental institutions of modern societies. This is why they believe “The Dangerous Child” movement is necessary.

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