|German polymath Johann Goethe studying in Frankfurt in the years circa 1769 to 1772 during which time he began to do experiments in chemistry in a search to uncover a secret principle of nature and the universe.|
In a 1678/79 letter to Irish chemist Robert Boyle, English chemical-physicist Isaac Newton was preoccupied with the phenomenon of elective affinity among chemicals, and stated: 
“There is a certain secret principle in nature by which liquors are sociable to some things and unsociable to others. Thus water will not mix with oil but readily with spirit of wine or with salts.”Newton here, to note, seems to be making an unknowing citation of Empedocles and his chemical aphorisms.
The finalized efforts of Newton's search for this secret principle are found in his last and final philosophical, his 1718 Query 31, the the addendum that launched the chemical revolution.
In 1768 to 1769, at the age of 18 to 19, German polymath Johann Goethe (see: Goethe timeline), having been intrigued by the chemistry works of Susanne Klettenberg and Paracelsus, was conducting chemical experiments, over a draft furnace in his attic, to reveal, according to Austrian philosopher Rudolf Steiner, “the principle that permeates the whole universe.”  In a 1770 letter to Klettenberg, Goethe wrote: 
To elaborate further on what he was after during this period, from book twenty of his autobiographical 1814 Poetry and Truth, in reflection on these pre-1775 years, Goethe wrote how he was searching for a universal rule to explain the happenings of existence: 
“I perceived something in nature (whether living or lifeless, animate or inanimate) that manifested itself only in contradictions and therefore could not be expressed in any concept, much less any word. It was not divine, for it seemed irrational; not human, for it had no intelligence; not diabolical, for it was beneficent; and not angelic, for it often betrayed malice. It was like chance, for it laced continuity, and like providence, for it suggested context. Everything that limits us seemed penetrable by it, and it appeared to dispose at will over the elements necessary to our existence, to contract time and expand space. It seemed only to accept the impossible and scornfully to reject the possible.”
Goethe penned his solution of his search for his secret principle in his 1809 physical chemistry based novella Elective Affinities, which itself was based on Newton's Query 31 via the 1775 work of Swedish chemist Torbern Bergman.
On beauty, Goethe in 1888 (Ѻ) famously stated:
“Das Schöne ist eine Manifestation geheimer Naturgesetze, die ohne dessen Erscheinung ewig wären verborgen geblieben.”
Translations of which include: (Ѻ) (Ѻ)
“The beautiful is a manifestation of secret laws of nature, which, but for its apparition, would have forever remained hidden form us.”
“Beauty is a manifestation of secret natural laws that would have remained hidden forever if the beautiful thing had not appeared.”
“Beauty is a manifestation of secret natural laws, which otherwise would have been hidden from us forever.”
See main: Adams beliefIn 1863, American thinker Henry Adams, writing to Charles Gaskell, seems to have begun searching for a universal theory of existence, applicable, in a one nature manner, atoms to humans: 
“Everything in this universe has its regular waves and tides. Electricity, sound, the wind, and I believe every part of organic nature will be brought someday within this law. The laws which govern animated beings will be ultimately found to be at bottom the same with those which rule inanimate nature, and as I entertain a profound conviction of the littleness of our kind, and of the curious enormity of creation, I am quite ready to receive with pleasure any basis for a systematic conception of it all. I look for regular tides in the affairs of man, and, of course, in our own affairs. In ever progression, somehow or other, the nations move by the same process which has never been explained but is evident in the oceans and the air. On this theory I should expect at about this time, a turn which would carry us backward.”
This quote is discussed by American comparative literature scholar Matthew Taylor, noted for doing his 2008 PhD dissertation, in part, in Adams’ physics-based theory of human existence. Adams would spend the next 50 years on this subject, becoming one of the first dual pioneers, following Goethe, of human chemistry (see: HC pioneers) and human thermodynamics (see: HT pioneers).
The following is a 20 Aug 1949 response by German-born American Albert Einstein (IQ=220) to a letter he received on a query about his scientific motivation: 
“My scientific work is motivated by an irresistible longing to understand the secrets of nature and by no other feeling.”IQ | Secret principle seeker
The average IQ of a secret principle searcher is 222 (mean IQ of Newton (IQ=215), Goethe (IQ=230), and Einstein (IQ=220)).
The principle both Goethe and Newton were searching was known to them as chemical affinity. In 1882, following the publication of "On the Thermodynamics of Chemical Processes" by German physicist Hermann Helmholtz, the measure of chemical affinity came to be known as free energy or available energy, thus becoming the new secret principle (see: human free energy).
1. Newman, William R. (2003). Gehennical Fire: the Lives of George Starkey, and American Alchemist in the Scientific Revolution (Elective affinity, pgs. 231-34). University of Chicago Press.
2. Steiner, Rudolf and Barnes, John. (2000). Nature’s Open Secret: Introductions to Goethe’s Scientific Writings (pg. 7). SteinerBooks.
3. Gebelein, Helmut. (2002). “Alchemy and Chemistry in the Work of Goethe”, In: The Golden Egg: Alchemy in Art and Literature, pgs. 9-30. Galda & Wilch.
4. (a) Goethe, Johann. (1814). Poetry and Truth (book 20). Publisher.
(b) Schwartz, Peter J. (2010). After Jena: Goethe’s Elective Affinities and the End of the Old Regime (pg. 19). Publisher. Bucknell University Press.
5. Einstein, Albert. (1981). Albert Einstein: the Human Side (pg. 18). Princeton University Press.
6. (a) Adams, Henry. (1863). “Letter to Charles Gaskell”, Oct.
(b) Adams, Henry. (1982). The Letters of Henry Adams, Volume 1: 1858-1868 (editor: Jacob Levenson) (pgs. 395-96). Harvard University Press.
(c) Stevenson, Elizabeth. (1997). Henry Adams: a Biography (pg. 69). Transaction Publishers.
(d) Taylor, Matthew A. (2008). Universes Without Selves: Cosmologies of the Non-Human in American Literature (pg. 108), PhD dissertation, Johns Hopkins University. ProQuest, 2009.