Sympathy is derived from the classical Greek συμπάθεια, or fellow (συμ)-feeling (πάθεια). A solid Latin translation would be compassio. Unfortunately, whatever is exactly meant by "sympathy," to English ears "compassion," that is, "a feeling of wanting to help someone" would seem to denote merely a sub-set of sympathy.* While "sympathy" does appear (with related concepts like harmony, natural friendship, etc.) in Plato and Aristotle, it tends to be originally identified with Stoic thought; it was also taken up and developed in non-trivial ways by Plotinus, Pliny, Vetrivius, and Galen (amongst others). Use for the concept was re-discovered in the Renaissance and -- as I learned from the distinguished scholar, Ann Moyer, -- promoted not so much by Ficino, but by Erasmus and Fracastoro. Even though in Fracastoro sympathy itself had a properly atomistic explanation, the concept was banished by Descartes and lumped with the to-be-discarded occult (see Principles of Philosophy 4.187).
Given the diversity of usages of 'sympathy' within the context of very different philosophical aims, one might doubt that there is a single, underlying concept rather than a host of family resemblances. Even so, while editing a forthcoming volume on the history of the concept, I came to think that one can identify the four following features that are incorporated in most usages of the term, 'sympathy.'
- Sympathy is used to explain apparent action at a distance.
- The very possibility of sympathy presupposes that it takes place among things that are in one sense or another alike (sometimes within a single being/unity/organism) to be contrasted with the antipathy (ἀντιπάθεια) of un-alikes. I call this condition of the possibility of sympathy, "The Likeness Principle" (or TLP; recall).**
- The cause(s) of sympathy is invisible to the naked eye.
- The effect(s) of sympathy can be (nearly) instantaneous.
Obviously, in the hands of different thinkers there will be a great deal more of fleshing out and linkage to other important commitments and concepts. Even so, these four features allow what we might call very 'naturalistic' accounts of sympathy. There is, thus, no necessary connection with the occult or magic when one deploys a sympathetic explanation. This fact helps explain the remarkable revival of the fortunes of sympathy in sober thinkers like Hume, Adam Smith, Sophie De Grouchy, Mill (etc.).
Of course, even if one is comfortable with causes spread out over great distances with simultaneous effects (recall my post on Gilbert and Newton), the TLP is open to various abuses. In particular, one might be tempted to treat the TLP not so much as a condition of possibility or as a constraint on explanation, but as itself the explanans of sympathy. To be sure, the TLP as explanans is neither an appeal to a supernatural cause nor itself invoking anything unintelligible. But explaining by way of the TLP does seem to fall short in specificity (say, of the mechanism, force, etc.).
Of course, sometimes an appeal to sympathy where at bottom the TLP does the explanatory work might be the best one can do for a whole range of naturally recurring phenomena. This fact might help explain why sympathy is an explanatory concept that, in fact, regularly gets banished and reinvented in a whole range of serious intellectual enterprises.
* Empathy is much more recent coinage.
**I learned the significance of the TLP from Eyjólfur Emilsson and René Brouwer.