Re: first draft of workshop report

John Josephson (jj@cis.ohio-state.edu)
Sat, 28 Sep 1996 11:09:02 -0400

The summary of the ECAI'96 workshop on Abductive and Inductive
Reasoning (DRAFT September 20, 1996 by Peter Flach and Antonis Kakas) is
so well written that I doubt the claim that it is a first draft. :-)

It certainly has my presentation summarized well. I am gratified to
have been convincing on the point that explanation is a matter of
causality rather than deductive entailment. Representing explanation as
entailment confuses, in my opinion, Causality, which is žin the world,Ó
with Entailment, which is žin the mind.Ó Of course, mental causation
exists, e.g., where decisions cause other decisions, which complicates
the simple distinction by pointing out that the causal žworldÓ includes
mental processes, but that should not be allowed to obscure the basic
point not to confuse an entailment relationship with the objective,
causal grounds for that relationship.

Explanations give causes. Explaining something, whether that something
is particular or general, gives something else upon which the first
thing depends for its existence, or for being the way that it is. The
bomb explosion explains the plane crash; the statistics relating smoking
and heart disease are explained by the mechanisms that connect the
ingestion of cigarette smoke with effects on the blood vessels of the
heart. Often in science, explanations are given for empirical
generalizations, the explanations appealing to a ždeeperÓ level of
structure and mechanism. Why does it grow cold in the winter? Because
the sun, being lower in the sky, and the sunŪs light striking at a lower
angle, warms the earth less. Explainer and Explained may be general or
particular, and accordingly, žinference to the best explanationÓ may
apply to generals or particulars.

The draft report mentions the question of the relation between
explanation and prediction. It is tempting to think that they have
žopposite chronology,Ó predictions projecting forward in time and
explanations projecting backwards, but I think that time is not the
essence of the matter. The temporal asymmetry results when explanation
and prediction are based on mechanical or žefficient causationÓ
(Aristotle, rendered into English). For other forms of causation, say,
teleological or final cause, explanations proceed from effect to cause,
and predictions may proceed from cause to effect, but the simple
temporal asymmetry is lost. For example, the existence of the spout on
the teapot may be explained by its purpose for pouring tea, and the need
for some means of pouring predicts the existence of something like the
spout. Even for efficient causation, the cause and effect may be
simultaneous, such as for žsustaining causes.Ó The heater & thermostat
maintain the temperature of the room. The temperature of the room is
explained by the existence and operation of the heater & thermostat; the
proper operation of the heater & thermostat predict the temperature of
the room; but all occur simultaneously.

Note, too, that while predictions are often based on reasoning from
cause to effect, that is not the only way in which predictions may be
licensed. For example I predict the weather tomorrow by appealing to
the authority of the weatherman, without knowing about the causes.

.. john ..