When speaking about causality, you should consider this: there are essentially two levels of contexts where natural dynamics occur. First, the level determined by our perception, and second, what we can call physical. I personally consider that Kant's Critique Of Pure Reason is the ultimate reference to such approach.
Russell stated that... "the law of causation,… is a relic of a bygone age, surviving, like the monarchy, only because it is erroneously supposed to do no harm". I consider such point of view completely wrong, under the light of the kantian approach. It would be this:
first, we have the context determined by our perception. What Kant named phenomena. Causality is a necessity on this level. Our understanding is basically the capacity to establish relationships between mental concepts, and causality is just that, except that time is involved. An example of a relationship is the knowledge that bachelors are single. The concepts bachelor and single are different in our mind, but they are clearly related. As said, causality is the same thing involving time, that is, the relationship is just sequential. For example, if you put your hand in quiet water, and move it, waves will be produced. What is essential here is that there's a mental relationship between the fact of moving your hand (adequately), and the 100% of probabilities that waves are produced (in proper conditions). That is causality: a knowledge that a fact will always trigger another related fact. Note apart, the quantum world is probabilistic, and our perception has to deal with probabilities, not certainties. Russell is wrong upon this context: causality is part of the essential framework of our knowledge.
second, the context that Kant called the noumena, what really happens in the physical reality, but we don't have access to. At such level, there are no things, no systems, therefore, no relationships. Nature is a fuzzy stuff where there are no boundaries. What we call fundamental particles are just fluctuations in quantum fields. Russell is right about causality, at this level. If we need to apply causation rules in this context, we are forced to "thingify" nature. We need to establish boundaries, that define things, objects and then we can establish relationships, and then we would have a relative understanding of causality in this context. But that doesn't work. As said, in QM, the universe is not causal, but probabilistic. A teacher used to state that to get a notion of this idea, you can use the same example of the hand waving into the water. Physically, it's a mess of changes, which cannot be written as equations. When and where does a water wave exists? It even depends on the point of view! What is the influence of the hand? We only can write equations if we "thingify" nature. But even if we are formal, things become probabilistic: there's no way to accept that 100% of times a hand woven into the water will produce waves. So, causality is definitively not a fact in this context.