The Limits of Physical Reality
In the modern vernacular, we might wish to describe physical reality using the term: WYSIWYG, i.e. what you see is what you get, and in some ways, if the perception of physical reality is subjective, this position might be as good as the next.
However, by the 18th century, Newtonian mechanics had become the accepted explanation by which any phenomenon could be explained in terms of a process proceeding from cause to effect. It provided the scientific rationale to Aristotle's philosophy and, as such, was thought to provide a deterministic description of physical reality. Although, in the context of this era, many would have preferred the following interpretation:
God created the world as a perfect machine, which required no further interference.
Of course, this may have only been acceptable to a deist, not a mainstream theist. However, as a consequence of this implied determinism, every event, including human cognition and action, had also to be causally determined by a series of events that led to the observed effect. As such, it was a perception of reality in which random chaos could not exist and led to the idea of a `clockwork universe`.
However, history shows us that while Newton’s ideas may have helped change our perception of reality, he was still very much a product of an earlier worldview; governed by Christian doctrine. As such, he was effectively submerged in a view of reality dominated by the prevailing religious culture in which he lived. Therefore, it was natural that many seemingly unanswerable questions about the reality of the world had to ultimately be deferred to God. However, almost in contradiction to Newtonian science, most theological beliefs also implied a wider definition of reality, which had to include not only the existence of the 'physical world' but also the existence of a 'metaphysical heaven' that transcended the laws governing physical reality. While some people still hold to this view, science, by its very nature is forced to seek some form of verification to any claim of a metaphysical extension to physical reality.
Even prior to the 20th century, there was clearly a dichotomy in these positions, which could not be resolved by a single perception of reality. While, today, we might talk of extending physical reality by entering a virtual reality or artificial reality simulation, the reality of a metaphysical heaven was clearly just as tangible to those who truly believe in the idea of heaven and hell. So, in many respects, we had a classical deterministic description of physical reality, i.e. the world, which had to co-exist with the generally accepted worldview at that time, which demanded a non-deterministic metaphysical reality, i.e. heaven.
However, as it would turn out, the 20th century world of science
would throw further doubt on both these views of reality and question
the very nature of physical existence, at least, as perceived by humanity.