not attempt to discover "first" causes.

[Sidenote: Science of Cause and Effect]

The practical scientist ascribes all sorts of qualities to electricity
and lays down many laws concerning it without having the remotest idea
as to what, in the last analysis, electricity may actually be. He is not
concerned with ultimate truths. He does his work, and necessarily so,
upon the principle that for all practical purposes he is justified in
using any given assumption as a working hypothesis if everything happens
just as if it were true.

The practical scientist applies the term "cause" to any object or event
that is the invariable predecessor of some other object or event.

For him a "cause" is simply any object or event that may be looked upon
as forecasting the action of some other object or the occurrence of some
other event.

The point with him is simply this, Does or does not this object or this
event in any way affect that object or that event or determine its
behavior?

[Sidenote: Causes and "First" Causes]

No matter where you look you will find that every fact in Nature is
relatively cause and effect according to the point of view. Thus, if a
railroad engine backs into a train of cars it transmits a certain amount
of motion to the first car. This imparted motion is again passed on to
the next car, and so on. The motion of the first car is, on the one