The causal principle and real powers

Whatever is actual only by reception, transition or composition requires an actual ground proportioned to that dependence, while a first cause is not placed under the same requirement as caused beings.

Causality is not the simplistic claim that every thing has a cause; it concerns the communication, reception and dependence of actuality.

The first distinction to hold in view is cause in becoming and cause in being: A builder is required for the house to come to be; the materials and structural order remain causes of its continued being. Creatures require divine conservation because their act of existence remains received. This is not a preliminary definition to be memorized in isolation. It is the point at which an otherwise plausible objection either becomes exact or is shown to trade upon two different meanings.

The causal principle arises from the intelligibility of change and dependence. A merely potential state does not actualize itself precisely as potential. An effect whose actuality is received cannot be its own adequate source in the same order. The argument does not begin with the universal proposition “everything has a cause,” which would immediately include God and produce a contradiction. It begins with what is changed, caused, composed, contingent or participated.

Real causal powers belong to substances according to their forms. Fire heats, an acid reacts, an eye sees and an intellect understands because each has a determinate actuality and capacity. Regularity is evidence of powers; it is not their creator. To reduce causality to a sequence of events leaves unexplained why one event is productive, why interventions work and why counterfactuals have the structure they do.

Causes must be proportioned to effects. A cause cannot formally give what it lacks in every mode, although it may contain the perfection virtually or eminently rather than in the same material manner. A teacher causes knowledge without losing it; the sun causes heat without being a burning coal. This principle is essential when reasoning from finite intelligence and goodness to a first cause: the cause contains the perfection without creaturely limitation.

Causal plurality is not competition with God. Created causes are genuine because the first cause gives them being, natures and powers. Divine causality is more intimate than creaturely causality and operates on a different level. God’s causing an act does not make the human cause unreal, just as an author’s causality does not turn the characters’ actions within the story into the same kind of cause. The analogy is limited, but it shows why “God or nature” is a false dilemma.

Cause in becoming and cause in being

A builder is required for the house to come to be; the materials and structural order remain causes of its continued being. Creatures require divine conservation because their act of existence remains received.

Principal and instrumental cause

A principal cause acts through its own power in the relevant order; an instrument acts through power received from the principal while contributing its proper disposition.

Per se and per accidens cause

A cause acts per se according to its power; an accidental effect follows from the intersection of causal lines, as when digging for a foundation discovers treasure.

Necessary and contingent causation

A cause may determine an effect necessarily or act through contingent and free modes. Causality is broader than deterministic necessitation.

Aristotle · Physics II · Thomas Aquinas · Summa Contra Gentiles I.13 · Summa Theologiae I q.2 a.3

For the causal principle and real powers, the controlling readers are Aristotle · Physics II, Thomas Aquinas · Summa Contra Gentiles I.13, Summa Theologiae I q.2 a.3. Open the cited question or work in full: compare the argument actually made, the exact Latin or Greek terminology where available, and the authority proper to the genre. The source route is part of the proof, not a decorative bibliography.