The denial of free will, of course, was my starting point. My 2nd assumption, CAUSALITY, proclaims that "All effects have an infinite number of material causes." I had no need for uncaused effects, seeing such claims as non-scientific (a different book, rewritten many times). As for the "feeling of freedom," I have it in spades like most everyone. Nevertheless, as part of nature, I don't claim to make any decisions that do not follow from previous actions. My view is that the ABC's of philosophy begin with the denial of free will, but that the indeterministic argument still exists because the opponents have their own agenda, which also is the opposite of mine. I don't spend much time on it because the debate is ancient and well-traveled by almost every philosopher who ever lived. CAUSALITY is an assumption, and like the other nine assumptions, cannot be proven until all the causes for all effects have been determined--an impossibility in an infinite universe. My contribution in The Scientific Worldview was to carry it through to the bitter/glorious end: the observation that everything in the universe is "natural." The argument, in an infinite universe, must be circular and never completely provable. One either likes it, or one does not.
In scientific philosophy we "like" theories that provide predictions that can be tested via experiment or further observation. For us, "truth" is how well our ideas fare in the external world. No idea ever fares perfectly well because each test involves an infinite number of variables. They are not all equally important, however, so accounting for as few as three or four variables often allows us to make adequate predictions. As stated in the 3rd assumption of science, UNCERTAINTY, "It is impossible to know everything about anything, but it is possible to know more about anything."