Insufficient Information

INSUFFICIENT INFORMATION

With the menu and with emergencies, logic can run out because there is not enough information around. With menus I often decide I’d like to eat the dish with the least calories, but I can only do that logically if the information is available. Otherwise I have to guess the information and then apply my logic.

In emergencies there might be insufficient time to make all the necessary logical deductions or to gather all the necessary information. This can happen in an emergency but it can also happen in sport, where the trajectory of a ball is in principle entirely governed by physics, but we can’t take all the necessary measurements in time to do the calculation before needing to hit the ball. It can also be because of lack of resources or physical feasibility. Chess is in principle a very logical game but it is massively complicated by the sheer number of different possible combinations of moves. As a result it is physically impossible to work through all the logical possibilities.

The weather forecast is also, in principle, entirely governed by some laws of physics. But we simply can’t gather all of that data. Also there might be so much data and so many tiny variables interacting that the system has in some places become “chaotic”. This is a mathematical term that means a system is entirely determined by all the data in theory, but in practice it is so sensitive to tiny fluctuations that in terms of forecasts it might as well be random, as we will never be able to collect data accurately enough to avoid those fluctuations. We should not blame the weather forecasters too much when the forecast is wrong, as the system is somewhat beyond the reaches of logic in practice.

Another example where we are hindered by complexity and insufficient data is in economics. Economic theories can be hampered by the fact that we don’t exactly know how humans are going to respond to certain situations. For example, some people say with certainty that raising the highest level of income tax will not bring in any more income, because the wealthiest people will simply leave the country. This might be true, but we can’t know for sure what people would actually do in a hypothetical situation. Anyone who claims to know has, at best, unreasonable certainty about their guesses.

It is possible that we could understand the world entirely logically in principle, but that is never going to happen in practice because we will almost certainly never have enough information. Any consequences involving human reactions to things are almost certain to be guesses about human behaviour, rather than logical conclusions.

This is one of the reasons that voting is so complicated in a “first-past-the-post” voting system. This is where the person with the most votes wins, and no second and third choices are taken into account, as in general elections in the UK and presidential elections in the US.1 If your main aim is to prevent a certain person being elected, you have to guess how everyone else is going to vote, in order to know who is the most likely candidate to beat the one you really object to. The trouble is that if many other people are also trying to guess, the situation becomes rather confused. Deciding in advance who to vote for as a group, in order to mount a robust opposition to a particular candidate, is also tricky. How do you know everyone will act as agreed? Issues of trust cannot be settled by logic alone.