The origins of modern science, what we call today the “Scientific Revolution,” the period of time that originated modern science (what we assume to be a rational, experimental activity) were rooted in what we would call “irrational” subjects of the occult sciences such as alchemy, astrology, and Pythagorean number mysticism. How did the occult sciences influence the course of natural philosophy from 1500 to 1700? Give specific examples from Copernicus through Isaac Newton to illustrate.
While many would like to disregard the influence that occult sciences have on modern hard sciences like chemistry and physics, the fact of the matter is that without them, many of our modern notions lack foundation. Occult sciences, such as alchemy, astrology, and Pythagorean number mysticism, just to mention a few, are often classified as "pseudo-science," emphasizing their roles as "science-like," but simply unworthy of being considered in the vast tradition we typically associate with mathematical hypothesis and experimentation. Closer examination and historical context reveals that this is not the case. Although the mindset of the mechanical philosophers, the emergent form of natural inquiry during the Scientific Revolution, began to suppress the validity of occult sciences, the tradition nevertheless perservered and even influenced aspects of mechanical philosophy.
The majority of what would become known as the occult sciences originate prior to the classial period. Alchemy, for example, has roots in Egpyt, as evidenced by its earliest known texts the Leiden and Stockholm Papyri. Their philosophical aspects, however, did not really come into play until Aristotle. He distinguished the properties of matter as being either occult or manifest. Manifest properties were properties that could be readily perceived by the senses, like color or taste. Occult, from the Latin occultus, means "hidden; these were attributes that could not be seen or perceived through the senses, such as magnetism or medicinal power. Occult properties were seen as mysteries of the universe, providing excellent fodder for those who wished to study the natural world and for those who desired to control it.
With the advent of the age of translation, medieval Europe underwent a transition to what became known as the Renaissance, or "re-birth." This re-birth referred to the rival of the scholarly and philosophical traditions of the ancient world, as well as its modifications and commentaries provided by the Arabic world. Due to the perservation of the texts by the meticulous Arabic scholars, the West managed to acquire texts not only by Aristotle, Plato, and Cicero, they also obtained the works of philosophers more interested in magical and occult matters. In any case, medieval Europeans, who had lacked the leisure to pursue such endeavors, were amazed at the sheer volume of thought from bygone years and began to place the past upon a pedestal. The Renaissance Humanists were particulary keen on this philosophy, and drew upon classical scholarship whenever it was possible. The appeal to ancient precedent was a common train of though indeed, for the Renaissance thinkers saw the ancients as adepts. That is, they possessed a hidden knowledge, and if one could study just enough, they too, would unlock nature's secrets.
Natural philosophy in 16th and 17th century Europe saw a shift away from the classical matter theory of Aristotle. The new age of mechanical philosophers, as they called themselves, endeavored to do away with all occult properites and explain phenomena only by means of physical corpuscular reactions. William Harvey, through autopsy and physical experimentation, expelled any notion of various secretive humours that ran through the body. Instead he displayed the body as a machine, the heart a mechanical bellows that pumps blood through valves and pathways through the force of its motions. Copernicus, Galileo, and Kepler all used the power of mathematics and telescopic observation to bring the celestial realm and the terrestrial realms together from their strict separation by Aristotilean philosphy. The celestial realm was no longer mystical but operated under a known (hypothesized) set of physical rules. Even the inclusion of naturalism into the picture eventually led to the exclusion of possibly the greatest of the occult: God. God's actions were simply unknown; His method of creating the universe as well as what actions He was performing. Mechanical philosophy did not seek to remove God from philosophy but eventually, by seeking natural causes to all phenomena, removed God from the minds of scientists as a natural cause to many of these phenomena. God still existed to many of the scientists, but He could no longer be used to explain natural causes since that would require admitting an unknown.
Of course, even with this shift, occult properites did not simply disappear. On the contrary, they simply became manifested in different forms in a more subtle fashion. Philippus Aureolous Theophrastus Bombastus von Hohenheim, better known as Paracelsus, a 16th Century German medical mystic and by all accounts a thoroughly disagreeable person, traveled around Europe accumulating knowledge and teaching the essential talent of taking power over nature for the use of medicine. According to Paracelsus, there were hidden or occult sympathies between the body and nature (certain herbs and/or metals) that one needed to discover in order to appropriately address medical conditions. Further, he brought astrology into medicine as well, linking parts of the body to the five planets known at the time, the sun, and moon. He considered wounds incurred at a certain phase of the moon, for example, to a moon-related body part to be "unluckier" than others, another example of the oft-seen microcosm/macrocosm paradigm. (Dear 51) He also stressed a practical knowledge of nature which would lead to discovering the occult sympathies. This practical approach was in conflict with the Aristotelean and Galenic approach to medicine and knowledge in general. The practical experimentation of Paracelsus' methods is also what persisted most from his methodology. The occult properties of his philosophy would not gain widespread popularity, but the experimental and practical approach would spread throughout medicine.
Other medical philosophers also incorporated occult tendencies into their practice. Jean-Baptiste von Helmont (1579-1644), a Belgian doctor, although he rejected the micro/macrcosm theory of medicine, different ailments of body parts relating to the planets and metals, was an advocate of wound sympathies. Best known by the "sword salve" example, the sympathies-theory which entailed that as the the flesh and the sword had interacted, they now possessed some connection. Therefore, the medicine was applied to the sword rather than the wound, which, in theory, would help cure the ailment. The tendency towards mechanical philosophy principles should be apparent. Even though he emphasized an interaction or connection between two particles, the relationship is similar to Newtonian attraction and repulsion.
Numerological mysticism is perhaps best seen in the works of Johannes Kepler. Being both deeply inquisitive and deeply religious, Kepler believed the universe was put together by God in a way that man could comprehend. God, therefore, in Kepler's estimation, is a geometer. In that line of thinking, Kepler asked questions such as "why are there only six planets, not more or less?" Kepler's answer to that question was delivered in Mysterium Cosmographicum in which he demonstrated that the distances between the planets equate to spheres inscribed in and around the five Platonic solids. Thus, Kepler posited, there are six planets because they are separated by ratios related to the five Platonic solids, of which there are only five. Kepler therefore saw nature as inherently mathematical, by God's hand to help man understand it.
Even the greatest scientists of the 17th and 18th century, including Isaac Newton, studied and were involved in the pursuit of what many now consider to be "pseduo-sciences." Because of Newton's ever meticulous nature, we have enormous amounts of writing in his hand on the subject of alchemy, both of his own study and transcribed from other works. He was involved in an exchange of information on the subject with two other very prominent historical philosphers; Robert Boyle and John Locke. Newton's works reveal alchemical influences if one knows where to look. Most obvious are his theories on attraction and repulsion, which lead to his famous theory of universal gravitation. Scholars like Betty Jo Teeter Dobbs and Richard Westfall have presented considerable evidence on the subject. Through their studies, we now know in the time preceeding The Principia, as well as during and for a short time afterwards, in which these theories of what we understand as gravity were put forth, that Newton was deeply involved in alchemy. Some of his other works also contain subtle traces of alchemial influence. Most noteworthy of these is Query 31, in which Newton incorporated known alchemical processes to discuss the various "temperments" so to speak, of substances when they are mixed together. He personified these mixtures, as well as larger interacting bodies, in terms of attraction and repulsion. This personification was the standard among alchemists, while the scientists of the time advocated a more "plain style" of prose. The connection between Newton's thought and his alchemical practice is evident.
What is likewise undeniable is that alchemy included chemistry. Alchemists explored the properties of various substances through distillation, precipitation, and other chemical methods still used today; this "wet" chemistry hasn't changed all that much. While pursuing transmutation or other alchemical ideas, alchemists discovered properties of materials that led to advances in metallurgy and dyes; they also worked as brewers and pharmacists, to name a few. Alchemists such as Agricola helped bridge the gap between the scholarly and the artisan or practical with their developments of practical materials from experimentation.
Overall, we can see that the occult sciences exerted considerable force over an array of Renaissance natural philosophers. The natural world was comprised of mysteries which could only be unlocked by means of the proper key. Whoever had the key controlled nature. Renaissance thinkers believed that the ancients possessed this key and thus poured over their tomes, trying to decipher hidden knowledge. The mechanical philosophers, although they certainly did not abandon this humanist viewpoint, opted to explain the world through more observable, measurable action. Their methods of practical knowledge and experimentation greatly influenced the process of modern science. Although they endeavored to remove the occult influence of the "pseudo-sciences," the rapid advances gained owe some debt to the occult tradition.