“This example shows also that the major premise, “If A then B” expresses B only as a logical
consequence of A; and not necessarily a causal physical consequence, which could be effective only
at a later time. The rain at 10 AM is not the physical cause of the clouds at 9:45 AM. Nevertheless,
the proper logical connection is not in the uncertain causal direction (clouds =⇒ rain), but rather
(rain =⇒ clouds) which is certain, although noncausal.
We emphasize at the outset that we are concerned here with logical connections, because some
discussions and applications of inference have fallen into serious error through failure to see the
distinction between logical implication and physical causation. The distinction is analyzed in some
depth by H. A. Simon and N. Rescher (1966), who note that all attempts to interpret implication
as expressing physical causation founder on the lack of contraposition expressed by the second
syllogism (1–2). That is, if we tried to interpret the major premise as “A is the physical cause
of B,” then we would hardly be able to accept that “not-B is the physical cause of not-A.” In
Chapter 3 we shall see that attempts to interpret plausible inferences in terms of physical causation
fare no better.”
To quote E.T. Jaynes:
“This example shows also that the major premise, “If A then B” expresses B only as a logical consequence of A; and not necessarily a causal physical consequence, which could be effective only at a later time. The rain at 10 AM is not the physical cause of the clouds at 9:45 AM. Nevertheless, the proper logical connection is not in the uncertain causal direction (clouds =⇒ rain), but rather (rain =⇒ clouds) which is certain, although noncausal. We emphasize at the outset that we are concerned here with logical connections, because some discussions and applications of inference have fallen into serious error through failure to see the distinction between logical implication and physical causation. The distinction is analyzed in some depth by H. A. Simon and N. Rescher (1966), who note that all attempts to interpret implication as expressing physical causation founder on the lack of contraposition expressed by the second syllogism (1–2). That is, if we tried to interpret the major premise as “A is the physical cause of B,” then we would hardly be able to accept that “not-B is the physical cause of not-A.” In Chapter 3 we shall see that attempts to interpret plausible inferences in terms of physical causation fare no better.”