Imparcticle said:So it is not neccesary to know precisely what the cause (say a force) is. Its effects let us know there is a force acting. Scientists (more specifically engineers) have obviously been able to accomplish many things without the knowledge of exactly what a force is in contrast to its effects. Therefore it is, as you say, uneccesary to know this. Is my understanding of this pragmatic?
Pragmatism refers to the doctrine of thought that we must attend to the consequences of a hypothesis. In other words, a hypothesis should describe two states of a system: one where the hypothesis is true, one where the hypothesis is false. If both states are indistinguishable, then our hypothesis is simply not worth investigating. So yes, I would characterise your comments as pragmatic. I don't think it's logically necessary, but I do regard it as an important principle from a scientific and methodological point of view. Verificationism is a stronger position, instead of saying "We don't care about hypothesis we can't test", they say "Entities we can not empirically verify do not exist". The problem is that the argument which purports to move from the epistemological statement to the ontological is a psychological argument, it's an appeal to our human desire for simplicity and elegance.
I haven't come up with a good comment on randomness... My "instincts" tell me that what it is truly random does not have a cause, for if it did then there would be an element of determinism which conflicts with what we want to mean by randomness. I also don't trust dictionary definitions.