Mill’s godson Bertrand Russell also had no doubt that causality and determinism were needed to do science. “Where determinism fails, science fails”, he said. Russell could not find in himself “any specific occurrence that I could call ’will’”. Charles Sanders Peirce “that the state of things existing at any time, together with certain immutable laws, completely determine the state of things at every other time (for a limitation to future time is indefensible). Thus, given the state of the universe in the original nebula, and given the laws of mechanics, a sufficiently powerful mind could deduce from these data the precise form of every curlicue of every letter I am now writing”. ...This is a fantasy, of course.
A rigorous analysis, from the foundations of physics, it is possible to prove that humans are not even animals or beings with the capacity to think (or decide), in fact, no being is capable of such an ability (according to physics). If the principles upon which physics is constructed are correct, a being able to decide is an impossibility, as we are a fraction of matter subjected to specific laws, the same laws used to describe a stone or any other object apply to humans as well (since humans, as we call it, does not have a privilege state in the universe). Every configuration of the universe in a given moment is predetermined by the conditions of the universe an instant before, dictating in a precise and absolute way the evolution of the entire system, inasmuch as the physical laws are strict and well defined.
I post this to point out that many people believe that determinism is a logical consequence of a scientific worldview. Those people have a big problem with quantum mechanics.