which determines the general dependence of entropy on probability. The universal integration constant
is the same for a terrestrial system as for a cosmical system, and when its numerical value is known for either system it will be known for the other; indeed, this constant
is the same for physically unlike systems, as above, where concurrence between a molecular and a radiating system was assumed. The last, additive, constant has no physical significance because entropy has an arbitrary additive constant and therefore this constant in (10) may be omitted at pleasure.
Relation (10) contains a general method of computing the entropy
from probability considerations. But the relation becomes of practical value only when the magnitude
of the probability of a system for a certain state can be given numerically. The most general and precise definition of this magnitude is an important physical problem and first of all demands closer insight into the details of what constitutes the "state" of a physical system. [This has been adequately done in the earlier part of this presentation. Later on pp. [27], [28], permutation considerations led us to define the probability W of a state as the number of complexions included in the given state.]