Re: On the issue of evidence
- In continuing to mull over the remarks of Prof. Davis and myself
with respect to inductive/deductive logic, I've come to the
realization that there is in fact a meaning for the term 'invalid
conclusion', to whit: a conclusion not supported by the evidence
(or premises). As can be seen, this meaning is related to the notion
of an invalid argument, wherein the premises do not support the
conclusion. I still cannot, however, imagine a meaning for 'invalid
As an example of deductive logic that might be useful as a case
study for further discussion, consider the following argument that
I myself have employed:
1) All "Nazarites from birth" were first-born sons.
2) Jacob the Just was a "Nazarite from birth".
3) Therefore, Jacob the Just was a first-born son.
As can be seen, (3) is a conclusion of some import for which (1)
and (2) - if true - provide powerful support perhaps not otherwise
available. Prof. Davis' claim, I take it, is that (1) and (2) are
inductively-derived. Even if so, however, it's clear from this
example that we do at least occasionally reason deductively from
such premises (even if the deductive argument is - as is often the
case - only implicit), and that thus the pointing out of logical
fallacies (which Prof. Davis decries) does not represent a basic
misunderstanding of the type of reasoning in which we engage.
Mt. Clemens, MI