An enquiry concerning the principles of natural knowledge

by Alfred North Whitehead

-space due to rest in the points of

-space is called the 'kinematic relation' between the two consentient sets, or between the two spaces.

8.3 The simplest form of this kinematic relation between a pair of consentient sets is when the motion of either set in the space of the other is a uniform translation without acceleration and without rotation. Such a kinematic relation will be called 'simple.' If a consentient group

has a simple kinematic relation to each of two consentient sets,

and

, then