|A circa 1,000AD listing of various elements and their alchemical symbols, during which time it was believed there existed some type of "sympathy" connection between astrology and the metals. |
In c.70BC, Greek philosopher Posidonius advocated a theory of cosmic "sympathy" (συμπάθεια, sumpatheia), the organic interrelation of all appearances in the world, from the sky to the earth, as part of a rational design uniting humanity and all things in the universe, even those that were temporally and spatially separate. (Ѻ)
“Nature persists and coheres by its own power without any help from gods. There is indeed inherent in it a kind of harmony or ‘sympathy’ as the Greeks call it. But the greater it is in its own right, the less need it be regarded as the work of some divine power.”— Cotta (Cicero) (45BC), On the Nature of the Gods
In 1000AD, the first attempts to represent chemical entities using "characters" or "symbols" was done some time in the late first century, when it was theorized that some type of "sympathy" connection existed between the astrology and the metals, thus, e.g., silver Ag, colored the same as the moon, was assigned with the chemical symbol of a crescent moon ☽, gold Au, colored the same as the sun, was assigned with the chemical symbol of the sun ☉ (or ☼), among other types of similar assignments.
In 1789, John Stewart, in his Moral Motion, possibly similar to Leonardo da Vinci, seems to have derived a vegetarianism philosophy based on his moral motion sympathy-centric ideology; some of which seems to be elaborated on as follows: 
“A man in an enlightened state of nature will be averse to the violence necessary to procure subsistence by animal food, and the only violence he will permit, and that with extreme regret, will be the destruction of destructive creatures, whom he cannot change by education or prevent by restriction: both of which means he will first attempt, in order that the ‘sacred passion of sympathy’ may receive no callosity or diminution by hasty or voluntary violence.”
The concept "sympathy",particularly after the publication of Newton's "Query 31" (1718), in large part, seems to have been usurped and and or supplanted by "affinity", in large part.
The following are related quotes:
“Like Empedocles, Leo identifies cosmic attraction with love. But he points out three degrees of love—natural, sensible, and rational. By natural love he means those "sympathies" which attract a stone to the earth, make rivers flow to the sea, keep the sun, moon, and stars in their courses, etc. Burton (1652) agrees with Leo, and asks quaintly: ‘How comes a loadstone to draw iron to it . . . the ground to covet showers, but for love? . . . no stock, no stone, that has not some feeling of love. It is more eminent in Plants, Herbs, and is especially observed in vegetals; as betwixt the Vine and Elm a great sympathy,’ ‘Sensible’ Love is that which prevails among animals. In it Leon recognizes the higher elements of delight in one another's company, and of attachment to a master. ‘Rational’ Love, the third and highest class, is peculiar to God, angels, and men. But the inclination to confound gravitation and other natural forces with Love is not to be found among ancient and mediaeval authors alone. Paradoxical as it may seem, it is the ‘gross materialist’," Dr. Ludwig Buchner, who exclaims rapturously: "For it is love, in the form of attraction, which chains stone to stone, earth to earth, star to star, and which Cosmic Attraction and Chemical Affinities holds together the mighty edifice on which we stand, and on the surface of which, like parasites, we carry on our existence, barely noticeable in the infinite universe; and on which we shall continue to exist till that distant period when its component parts will again be resolved into that primal chaos from which it laboriously severed itself millions of years ago, and became a separate planet.”— Henry Finck (1887), Romantic Love and Personal Beauty 
“I am tempted to send Winiarski criticism. Why he called selfish and altruistic one hand on the other hand the forces of competition tends to be the balance of the moral world? Selfishness is it not by itself a principle sufficient to reconstruct the moral world the forces of attraction and repulsion that occur in any cosmic system? If these forces must be given a new name when carried out in this moral field, the words love and hate, or sympathy and antipathy, does not correspond with a more precise symmetry in attraction and repulsion, are not they not to each other more closely balances?”— Jules de Gaultier (1898), “Review of Winiarski’s Essay on Social Mechanics” (Ѻ) 
1. Partington, James. (1937). A Short History of Chemistry (pg. 22). Dover, 1989.
2. (a) Stewart, John. (1789). Travels to Discover the Source of Moral Motion (volume one) (Part II, §: The Arts, pg. 73) (Ѻ). Ridgway.
(b) Stewart, John. (1790). The Apocalypse of Nature: wherein the Source of Moral Motion is Discovered (volume two). Ridgway.
3. (a) Gaultier, Jules de. (1898). “History, Societies, Governments – Review: Doctor Leon Winiarski: Essay on Social Mechanics”, Revue Blanche, 16: 636-38.
(b) Jules de Gaultier – Wikipedia.
4. Finck, Henry. (1887). Romantic Love and Personal Beauty: Their Development, Causal Relations, Historic and National Peculiarities (section: Cosmic Attraction and Chemical Affinities, pgs 4-9). MacMillan.
● Knight, David. (2003). “Sympathy, Attraction and Elective Affinity”, Bulletin de la société d'études anglo-américaines des XVIIe et XVIIIe siècles, 56(56): 21-30.
● Schliesser, Eric. (2015). Sympathy: a History. Oxford University Press.