Editing Cosmological argument (section)

=== Accidental and essential ordering of causes ===

Aquinas refers to the distinction found in Aristotle's ''[[Physics (Aristotle)|Physics]]'' (8.5) that a series of causes may either be [[Accident (philosophy)|accidental]] or essential,<ref name="ICR">{{Cite web|url=http://digitalcommons.liberty.edu/cgi/viewcontent.cgi?article=1065&context=sor_fac_pubs|title=Infinite Causal Regress and the Secunda Via in the Thought of Thomas Aquinas}}</ref><ref name="IEPAI">{{cite encyclopedia|title=Aquinas: Philosophical Theology 2.b. |url=http://www.iep.utm.edu/aq-ph-th/#SH2b |last=Floyd |first=Shawn |encyclopedia=Internet Encyclopedia of Philosophy}}</ref> though the designation of this terminology would follow later under [[Duns Scotus|John Duns Scotus]] at the turn of the 14th century.<ref name=SEPScot/>

In an accidentally ordered series of causes, earlier members need not continue exerting causal activity (having done so to propagate the chain) for the series to continue. For example, in a generational line, ancestors need no longer exist for their offspring to continue the sequence of descent. In an essential series, prior members must maintain causal interrelationship for the series to continue: If a hand grips a stick that moves a rock along the ground, the rock would stop motion once the hand or stick ceases to exist.<ref name=feser1>{{cite book |last=Feser |first=Edward |year=2009 |title=Aquinas: A Beginner's Guide |publisher=Oneworld Publications |isbn=978-1-851-68690-2}}</ref>

Based upon this distinction [[Frederick Copleston]] (1907–1994) characterises two types of causation: Causes ''in fieri'', which cause an effect's ''becoming'', or coming into existence, and causes ''in esse'', which causally sustain an effect, in ''being'', once it exists.<ref>{{cite book|last1=Joyce|first1=George Hayward|year=1922|title=Principles of Natural Theology|location=New York|publisher=Longmans Green}}</ref>

Two specific properties of an essentially ordered series have significance in the context of the cosmological argument:<ref name=feser1/>

*A first cause is essential: Later members exercise no independent causal power in continuing the series. In the example illustrated above, the rock derives its causal power essentially from the stick, which derives its causal power essentially from the hand.
*All members in the causal series must exist simultaneously in time, or timelessly.

[[Thomism|Thomistic]] philosopher, R. P. Phillips comments on the characteristics of essential ordering:<ref name=RPP>{{cite book |last=Phillips |first=Richard Percival  |title=Modern Thomistic Philosophy, Vol. II |publisher=Editiones Scholasticae |date=2014 |isbn=978-3868385403}} pp 284-285.</ref>

:"Each member of the series of causes possesses being solely by virtue of the actual present operation of a superior cause ... Life is dependent ''inter alia'' on a certain atmospheric pressure, this again on the continual operation of physical forces, whose being and operation depends on the position of the earth in the solar system, which itself must endure relatively unchanged, a state of being which can only be continuously produced by a definite—if unknown—constitution of the material universe. This constitution, however, cannot be its own cause ... We are thus irresistibly led to posit a first efficient cause which, while itself uncaused, shall impart causality to a whole series."