F=MA expresses a simultaneously changing relationship between different variables. There is a kind of causal relationship between them. An increase in mass causes a decrease in acceleration (where force is constant). But it is not the sort of cause and effect described by Hume. Rather, it is an interrelation between two aspects of the same whole... more like per se causality as described by Aristotle rather than Humean characterization of causality as essentially a relation between antecedent and consequent events. In this way it is ironic that Hume sought to emulate Newton by identifying a psychological analog to universal gravitation.
Commentary and discussion regarding science, faith and culture by Leo White