Chapter 8 endnote 6, from Lisa Feldman Barrett.
Some context is:
If instances of sadness occur with a pout and a slowed heart rate, then a fingerprint of “pout and slowed heart rate” may be the essence of sadness. Alternatively, the essence might be an underlying cause that makes all the instances of sadness the emotion they are, such as a set of neurons. [...] Philosophers debate over the definition of essences.
Some philosophers (such as Plato) consider an essence to be a set of features that are shared by all perfect (or Platonic) instances of a category; a set of necessary and sufficient features. This stems from Plato’s cave: what we see are the shadows that are cast on the wall of the cave – the shadows are cast by the ideal, perfect form (the essential Platonic form). So, the ideal form of something (the perfect instance) is its essence.
For other philosophers such as John Locke, the essence is a deep, underlying property, not readily observed but shared by all instances. The superficial features are caused by this underlying, unchanging essence: “The real internal, but generally … unknown constitution of things” upon which their discoverable qualities depend.
The classical view of emotion embodies both types of assumptions – mythical neurons (genes, or neurotransmitters) dedicated to an emotion are its causal essence, and its mythical fingerprint is the Platonic essence.
If you believe that an essence exists but don’t know what the essence is, that’s called psychological essentialism.
These two types of essences (causal mechanisms and fingerprints) refer to ways of describing what makes something a natural kind. Philosophers use the term “natural kinds” to describe categories that have firm boundaries in nature. The classical view presumes that each emotion like anger, sadness, fear, disgust, happiness, and a handful of others are natural kind categories with boundaries that can be discovered in nature. The mythical fingerprint is the set of necessary and sufficient feature that describe all instances of a given emotion category; it defines the kind of emotion by analogy. The emotion's underlying cause defines the category by homology.
Notes on the Notes
- Medin, Douglas L., and Andrew Ortony. 1989. "Psychological essentialism." In Similarity and Analogical Reasoning, Edited by Stella Vosniadou and Andrew Ortony, 179-195. Cambridge: Cambridge University Press.
- Barrett, Lisa Feldman. 2006. "Emotions as natural kinds?" Perspectives on Psychological Science 1: 28-58.