Newton advocated the view that atoms, conceived as small indivisible particles of matter (substance) and the void together accounted for the physical world as we, its observers, experienced it. A similar suggestion had been made two thousand year earlier by the Greek natural philosophers, e.g. Democritus (c. 400 BC), and was reaffirmed repeatedly by other Western philosophers without adding any observations or experimental investigations to support this view.
It had received support from both Plato and Aristotle although it was clear to them — and to others — that the supposition that the world was constituted in such a manner would have to remain entirely speculative. Methods to test whether indeed such “entitites” as atoms could be discovered — were not available. However there were some who believed that sooner or later suitable instruments would be invented to do so, a hope which helped sustain the wide-spread cosmological view that nature in its physical manifestations could be “revealed”, that the appropriate information would ultimately become available to us.
This optimistic notion received support from discoveries during the mid-17th century that microscopic single-cell organisms had been observed and studied by Leewenhoek in Delft, Holland, by adapting the earlier discovered telescope which had been successfully used to studied far-distant celestial bodies. It therefore seemed plausible to some to also assume that whatever governs the motions of stellar bodies also govern those on earth, that the quest for a unified, general theory of why and how bodies suspended in any media could be satisfied. Newton certainly cast his support for this position, as shown in his comments in his widely studied thesis on “Opticks” (1704-1706), a work which was to dominate natural philosophy for the next few hundred years.
It seems probable to me that God in the beginning formed matter in solid moveable particle of such sizes and figure and with such other properties and in such other propertied, and in such proportions to space, as most conduced to the end for which He formed them; and that these primitive particles being solid are incomparably harder than any porous bodies compounded of them, even so very hard as never to wear or break in pieces; no ordinary power being able to divide what God had made in one in the first creation. While the particles continue entire, they may compose bodies of one and the same nature and texture in all ages; but should they wear away or break in pieces the nature of things depending on them would be changed….And therefore that nature may be lasting, the changes of corporeal things are to be placed only in the various separations and new associations and motions of these permanent particles; compounded bodies being apt to break not in the midst of solid particles, but where those particles are laid together and only touch in a few points.
Readers will see to what extent this passage from Newton confirms his life-long commitment to a theological position which he had taken over from official dogma and doctrine. He not only refers to the pivotal position of the Hebrew God as a Creator of the universe but also his conviction — also found in Aristotle’s metaphysical writings — that whatever is observed as a genuine item of this world is part of a teleological narrative. It is the message articulate earlier — and better — that “There is a divinity that shapes our ends, rough hew them how we will” although its truth is equally debatable ( “Hamlet”, Act V) .
This narrative is not only pre-emptive, but strikes in advance of any pertinent evidence which could call it into question. It is formulated in a manner which cannot be contested either logically — or whose contradiction could be formulated in a way that makes these into issues which could be tested (checked) by physicalistic means, i.e. experimentally and in accordance with the strictures of experimental science, which Newton and many of his contemporaries believed were foundational to studying the “Book of Nature”.