(GR. μονή, ἠρεμία; Lat. quies, mansio, status ), the opposite of motion. It is the privation of motion in that which is receptive of motion but is not actually being moved. Rest in an initial state (terminus a quo ) is contrary to the motion that proceeds from it, but there is no strict contrariety between motion and rest in a terminating state (terminus ad quem ), since rest is the end and perfection of motion, the state of actuality to which motion tends. Likewise, motion is the cause of rest, and something is not the cause of its contrary. Motion and rest are in the same subject, although not both together.
There is a rest corresponding to each type of motion, so that a being may be in motion in one respect and simultaneously at rest in the possession of some state acquired by a different kind of motion. substantial change is not only absence of change.
Rest is measured by time, not by the indivisible now. Strictly speaking, only motion is measured by time, since time is the number of motion according to before and after. A body in the state of rest is a mobile being, and its repose has come about as the result of a motion and will cease when a contrary motion occurs. The duration of the repose between two such motions is measured by means of the duration of the motion of some other body.
Like motion, rest can be either natural and according to nature or unnatural and forced. Rest can be understood in an extended sense. When an agent ceases acting, it is said to come to rest. The mind rests in contemplation of truth and the appetites in the possession of good. The state of equilibrium is not so much rest as the balancing off of opposite forces. Homeostasis is a state of dynamic equilibrium that tends to maintain itself in living beings.
See Also: motion; reality.
Bibliography: aristotle, Phys., bk. 5, ch. 6. thomas aquinas, In 5 phys. 9–10.
[m. a. glutz]
"Rest." New Catholic Encyclopedia. . Encyclopedia.com. (August 14, 2018). http://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/rest
"Rest." New Catholic Encyclopedia. . Retrieved August 14, 2018 from Encyclopedia.com: http://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/rest