Friday, November 26, 2004

Causes, Associations & Signs

Theories about the workings of inference from evidence perhaps fall into three groups:
1. probabilistic causality
2. associationism
3. semiotics
The first approach holds that evidence works as evidence only if there is a causal connection between evidence and hypothesis.

The second approach holds that evidence works as evidence when experience shows a regular connection (to some degree or frequency) between evidence and hypothesis.

The third approach holds that matters which work as evidence function as signs of matters (hypotheses) beyond themselves.

  • The third approach, to be respectable, must be stripped of the turgid nonsense in which "semiotics" has been wrapped by many literary theorists.
  • Much of the theorizing about evidence in the American legal academy buys into the notion that evidence works as evidence only because of experienced or observed regularities in the occurrence of distinct events or phenomena -- that evidence works as evidence only because of the relative frequencies of distinct events or phenomena. But the law in practice is generally indifferent to the relative plausibility of these three seemingly-divergent accounts of evidence, inference, relevance, and probative value; viz., the law in practice accepts much evidence whose causal connection to hypotheses of interest is not demonstrated or demonstrable; it accepts some evidence whose probative force rests on a causal account rather than on observed association or for any other apparent reason; and judges administering the law of evidence accept much evidence as worthy of consideration even when neither a causal account nor observed regularities seem to provide any apparent reason for doing so.

    It is good that the law of evidence does accept any one of these three theories as orthodox and authoritative dogma. There are large grains of truth in all three accounts.

    The real question, presently unanswerable, is which account best accommodates all three types of sources of human empirical knowledge.

    I suspect that the best foundation for a comprehensive account of evidence and inference is laid by semiotic theory, the approach that emphasizes that evidence is an event or state that indicates or suggests a matter apart from, in addition to, or beyond itself.

    The view of evidence as essentially sign, or hint, is most readily compatible with the hypothesis that both the human brain (along with its appurtenances) and the cosmos happen to be wired in such a way that a human actor has the ability to see a glimmer of a new truth based upon one encounter with some event or state of affairs -- based, in other words, on an encounter with a unique event, a singularity. And only semiotic theory explains how evidence manages to prod the human imagination to attack complex problems in quite fruitful ways, in situations that are so complex, that have so many ingredients, that random conceptual walks even over aeons of time could not be expected to yield plausible conjectures.

    I will explain the above points in much more detail later -- in my promised book. Stay tuned!