Goodman's Theory Research Articles

Discussion: Reply to Ackermann

Permit me to reply to the recent note [1] in this journal by Robert J. Ackermann, concerning my critical comments (in [4]) on Nelson Goodman's entrenchment theory.

Formula for Thermal Accommodation Coefficients

A simple formula in closed form is proposed for the thermal accomodation coefficient from which the accommodation coefficient of a monatomic gas—solid system may be calculated from certain basic parameters of the system. The formula α(T)=1−exp(−T0/T)+α(∞) tanh{[(MT)1/2/α(∞)](a/λ)} exp(−T0/T)is obtained from consideration of certain aspects of Goodman's lattice theory of accommodation and from conclusions regarding certain properties of available experimental data. Adequate agreement is obtained of the formula with both the lattice theory and experimental data. Certain, corrections are applied to the lattice theory, and the gas—surface-potential interaction parameters relevant to the lattice theory are revised.

Nelson Goodman's Entrenchment Theory

One of the fundamental problems in the fields of inductive logic and the philosophy of science is the one concerning inferences or projections containing so-called “grue-like” or “pathological” predicates. This problem was first put into sharp focus by Nelson Goodman, who called it the “new riddle of induction.”Goodman has shown that the few attempts by others to solve this problem (which appear in the literature) are not adequate. However, very little has been written concerning Goodman's own attempt to solve the problem, namely his theory of entrenchment. The purpose of this article is to show that Goodman's entrenchment theory also is inadequate as a solution to the new riddle of induction. I shall try to do this by presenting two kinds of counterexamples to the entrenchment theory: one kind illustrating a general objection to the theory as a whole ; the other kind, specific objections to particular (vital) parts of the theory.