Occasionalism is a philosophical doctrine about causation which says that created substances cannot be efficient causes of events.
The ninth century theologian Abu al-Hasan al-Ash'ari argued that there is no Secondary Causation in the created order.
In response to the philosophers' claim that the created order is governed by secondary efficient causes (God being, as it were, the Primary and Final Cause in an ontological and logical sense), Ghazali argues that what we observe as regularity in nature based presumably upon some natural law is actually a kind of constant and continual regularity.
To posit an independent causality outside of God's knowledge and action is to deprive him of true agency, and diminish his attribute of power.
In the 12th century, the Islamic theologian Fakhr al-Din al-Razi expounded upon similar theories of occasionalism in his works.
In a 1978 article in Studia Islamica, Lenn Goodman asks the question, "Did Al-Ghazâlî Deny Causality?
One of the motivations for the theory is the dualist belief that mind and matter are so utterly different in their essences that one cannot affect the other.
The illusion of transient efficient causation, for Leibniz, arose out of the pre-established harmony between the alterations produced immanently within different substances.
[10] In 1993, Pierce College chemistry professor Karen Harding published the paper "Causality Then and Now: Al Ghazali and Quantum Theory" that described several "remarkable" similarities between Ghazali's concept of occasionalism and the widely accepted Copenhagen interpretation of quantum mechanics.
She stated: "In both cases, and contrary to common sense, objects are viewed as having no inherent properties and no independent existence.
Although the probability of such an event is very small, such an event is, nonetheless, still possible.Continuing from philosopher Graham Harman's work on occasionalism in the context of object-oriented ontology,[12][13][14] Simon Weir proposed in 2020 an alternate view of the relationship between quantum theory and occasionalism opposed to the Copenhagen interpretation, where virtual particles act as one of many kinds of mediating sensual objects.