are extrinsic. It never parts with its patrimony. To me, the
'nature' of a thing seems not to be so private or fixed. It may consist
entirely of bonds, stocks, franchises, and other ways in which public
credit or the right to certain transactions is represented.... At any
rate, relations or transactions may be regarded as wider or more primary
than qualities or possessions. The latter may be defined as internal
relations, that is, relations _within_ the system that constitutes the
'thing.' The nature of a thing contains an essence, i.e., a group of
characteristics which, in any given system or context, remain invariant,
so that if these are changed the things drop out of our system ... but
the same thing may present different essences in different contexts. As
a thing shifts from one context to another, it acquires new relations
and drops old ones, and in all transformations there is a change or
readjustment of the line between the internal relations which constitute
the essence and the external relations which are outside the inner
circle...."

Before continuing, however, I wish to make certain interpretations of
these statements for which, of course, Professor Cohen is not
responsible, and with which he would not be wholly in agreement. My
general attitude will be shown by the first comment. Concepts are only
means of denoting fragments of experience directly or indirectly given.
If we then try to speak of a "nature of a thing" two interpretations of
this expression are possible. The "thing" as such is only a bit of
reality which some motive, that without undue extension of the term can
be called practical, has led us to treat as more or less isolable from
the rest of reality. Its nature, then, may consist of either its
relations to other practically isolated realities or things, its actual
effective value in its environment (and hence shift with the environment
as Professor Cohen points out), or may consist of its essence, the
"relations within the system," considered from the point of view of the
potentialities implied by these for various environments. In the first
sense the nature may easily change with change in environment, but if it
changes in the second sense, as Professor Cohen remarks, it "drops out
of our system." This I should interpret as meaning that we no longer
have that thing, but some other thing selected from reality by a
different purpose and point of view. I should not say with Professor
Cohen th