Thursday, May 24, 2007

Kant, Locke, Hume and causality

One of the issues of contention between the enlightenment philsophers Kant, Locke and Hume was causality. Hume stated that causal connections were mere habits of the mind that we were never philosophically justified in taking. Kant said that causal connections are the minds bridge between sensory stimulus and pure concepts and are made possible by apriori concepts like space and time that pre-exist in the mind independent of any experience we might have. Locke stated that understanding is created by the mind reflecting on sensory input-this understanding would include understanding causal connections.

How do we come to say that 'A' causes 'B'? Consider a collision of pool balls. Pool ball 'A' approaches pool ball 'B', we hear a click and the second ball zooms off. A precedes B in time and occurs in the same physical space. It does so very reliably so we say that A causes B. I don't know about you, but I hear echoes of all three philosophers in this.

The preceding example was of physical things. We might also say that 'oppression causes rebellion' or 'rising prices cause demand to fall'. That would be a different notion of causality since it involves social phenomena and our notions of free will might enter into the picture. Statements of social or economic causality might only be true on the average. The case is complicated still further by three different kinds of physical causality recognized by physicists: deterministic causality, quantum causality and ill-conditioned causality. Deterministic causality (like pool ball collisions) is 'one event has one and only one set of causes'. Quantum causality (like subatomic particle collisions) is 'one set of causes may initiate any one of a set of effects'. Ill-conditioned causality (like the weather or traffic patterns) is 'apparently identical causes may have wildly varying effects'.

I think humans have a built-in psychological hunger for causal connections. (there is my nod to Kant and his apriori concepts). At a certain age, human children ask why? why? why? until their parents go mad. When confronted with an unexpected, especially traumatic event, humans console themselves with causal explanations. Religions often provide these explanations which are so comforting when humans are faced with death or loss. Lack of an ability to explain the cause of a traumatic event can be psychologically devastating and result in loss of confidence and the will to engage in life's activities. My point here is that, whether the universe was causal or not, humans would seek and invent causal explanations anyway.

Next, there is the existence of some pretty convincing physical laws which really do seem to work all the time. Gravity, electromagnetism, nuclear force, conservation of energy, momentum, angular momentum. These really work. Pretty hard to explain if the world really isn't causal and this is just wishful thinking. Sorry Mr. Hume, I think we really can and must accept causality.

So I have a species with a built-in desire for causal connections and a universe which happens to be causal. That the universe should so fit in with our desires is a pretty amazing thing. It is under no obligation to conform to our fantasies or desires, but in this case, it does. Is this an ontological argument for God? Is it a case of simply our being a product of a causal universe? If so, I wish I desired reality more consistently. It might improve my state of happiness.

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