© Roger M Tagg 2009 revised 2010
Welcome to FROLIO – a new attempt to merge philosophy and the "semantic web" . This website is under continuing development.
By a Rule, I mean an expression that says "if X happens, then we should do action A". By a Constraint, I mean a statement that says "situation C must never arise".
Some people split the X part of Rules into 2 parts E and C; E is the "event", i.e. whatever triggers the situation or causes the rule to be invoked, while C is the condition that is tested when deciding whether to do action A or not. A Constraint is little more than a rule which says that if someone or something threatens to reach the situation C, then they must be prevented, and things must be kept within the stated limits.
Rules and constraints are popular in two environments. One is where some person or group in authority over others, and wants to set a standard for how things should happen in the society concerned. National, state and by laws are an obvious example, as are procedures within an organization, industry or educational establishment. The other environment is computer systems, where the physical world of humans and machines is supposed to be under the control of the system. Constraints appeal to the more mathematically-inclined types in IT, as they afford the possibility of being processed by known programs or "algorithms".
I like to distinguish 4 assumptions one has to make in a rule-based approach:
In my view, the fundamental limitation is that the models we build to describe and control the "real world" are only approximations. In order for these models to be useful, some of the detail, and hence the scope for unpredictable happenings, has to be left out - otherwise the models would be too complex and one might as well experiment using "trial and error" in the real situation.
Constraints may be OK as a model when physical material enforces the constraint by its nature, e.g. a liquid contained in a watertight container, a prisoner shackled by chains to a post, or a goat tethered. But vessels can leak, and prisoners and goats - not to mention harry Houdini - can escape. In this sense, the mechanisms to enforce the rules and constraints are never perfect; materials may corrode, break or stretch, warders may be corrupt, and the justice system may be over-stretched.
When we are dealing with human mental and manual activities, constraints are even less good as a modelling construct than rules. There may be rules or procedures, but the humans may choose not to follow them, and can decide either to bear the consequences or gamble on not getting caught.
Mathematics (I should know) is a field where we can define things exactly and things are "true by definition". Even with Physics, where limitation of speed to that of light is said to be a strict constraint, we are dealing with models as often as we are with observations. The criticism could be made of Frolio that it cannot be "formalized" to enough of an extent to predict any useful conclusions. I do agree that we ought to be able to do better than resolve matters by arguments using words. However we still have Statistics -which is all about variability and unpredictability. I wish that weather forecasters would give us a more statistical idea of whether or not it will rain tomorrow. I have heard forecasts that talk about a 40% chance of rain, but here in Australia we only get one statement (fine, showers, rain etc) and one temperature estimate.
Finally, something that is a constraint at one time may not remain so indefinitely. Man has (allegedly) landed on the moon. A computer can perform millions of calculations per second. We have television, atomic bombs, drugs to treat many diseases, intercontinental air travel and so on.
"... logic (just like geometry and arithmetic) applies only to fictions of our own creation. Logic is our attempt to understand the actual world by using a scheme which we ourselves have made up; in other words, to make it amenable to make it amenable to schemes of formula and calculation which we have invented for ourselves alone." (Nietzsche)
"The fundamental fact here is that we lay down rules, a technique, for a game, and when we follow the rules, things do not turn out as we had assumed; that we are therefore, as it were, entangled in our own rules. The entanglement in our rules is what we want to understand (i.e. to get a clear view)." (Wittgenstein, later works)
Index to more of these diatribes
Some of these links may be under construction – or re-construction.
This version updated on 25th May 2010
If you have constructive suggestions or comments, please contact the author rogertag@tpg.com.au .