object is an active condition
for the situation of a patch of colour behind it, due to the reflection
of light in it.

Thus the origin of scientific knowledge is the endeavour to express in
terms of physical objects the various _roles_ of events as active
conditions in the ingression of sense-objects into nature. It is in the
progress of this investigation that scientific objects emerge. They
embody those aspects of the character of the situations of the physical
objects which are most permanent and are expressible without reference
to a multiple relation including a percipient event. Their relations to
each other are also characterised by a certain simplicity and
uniformity. Finally the characters of the observed physical objects and
sense-objects can be expressed in terms of these scientific objects. In
fact the whole point of the search for scientific objects is the
endeavour to obtain this simple expression of the characters of events.
These scientific objects are not themselves merely formulae for
calculation; because formulae must refer to things in nature, and the
scientific objects are the things in nature to which the formulae refer.

A scientific object such as a definite electron is a systematic
correlation of the characters of all events throughout all nature. It is
an aspect of the systematic character of nature. The electron is not
merely where its charge is. The charge is the quantitative character of
certain events due to the ingression of the electron into nature. The
electron is its whole field of force. Namely the electron is the
systematic way in which all events are modified as the expression of its
ingression. The situation of an electron in any small duration may be
defined as that event which has the quantitative character which is the
charge of the electron. We may if we please term the mere charge the
electron. But then another name is required for the scientific object
which is the full entity which concerns science, and which I have called
the electron.

According to this conception of scientific objects, the rival theories
of action at a distance and action by transmission through a medium are
both incomplete expressions of the true process of nature. The stream of
events which form the continuous series of situations of the electron is
entirely self-determined, both as regards having the intrinsic character
of being the series of situations of that electron and as regards the
time-syste