Maybe the example could be a bit clearer. In the example, the point is that they don't know all of the variables. I would define this sort of (faulty) determini

Maybe the example could be a bit clearer. In the example, the point is that they don't know all of the variables. I would define this sort of (faulty) deterministic reasoning literally as not accounting for hidden variables. If we know absolutely every variable and potential confounding factor, then deterministic reasoning works and is valid. The problem is that in pretty much every case we don't know all of the variables, and so we can't generalize from a finite number of cases. The solution that the author is giving is to think in probabilities instead.