“Neuroscience has much to learn from Hume’s philosophy of emotions
Richard C. Shais professor of literature and an affiliate professor of philosophy, as well as an affiliate of the Center for Behavioral Neuroscience, all at the American University in Washington, DC. His books include Perverse Romanticism: Aesthetics and Sexuality in Britain, 1750-1830 (2009) and Imagination and Science in Romanticism (2018).
We are in the midst of a second Humean revolution. In his Treatise of Human Nature (1739-40), the Scottish philosopher David Hume argued that: ‘Reason is, and ought only to be the slave of the passions …’ By ‘passions’, Hume meant what we now call emotions. What gave him such faith in the passions that he could accept reason’s enslavement to them? Hume understood reason to be incapable of producing any action, and the passions to be the source of our motivations. So he insisted that we must attend to the passions if we want to understand how anything gets done. Much recent neuroscience has found that human rationality is weaker than is commonly presumed, and the emotions make it possible to make decisions by granting certain objects salience. Why does this second Humean revolution matter and what, if anything, can the second revolution learn from the first?
By and large, scientists until recently avoided the emotions as too subjective, too imprecisely defined. Yet once Darwinian evolution and neuroscience supported the link of emotion to action, emotions began to gain more attention from scientists. In his book The Strange Order of Things (2018), Antonio Damasio, one of the most influential neuroscientists today, defines the affects and emotions as ‘action programmes’, and by this he connects emotions to homeostasis, the process by which we keep ourselves alive. How better to grant the emotions scientific weight than to make them the key to human survival? Neuroscience also supports a growing recognition of the connections between the brain’s perceptual and motor systems; this has led scholars such as Francisco Varela, Evan Thompson, Andy Clark and Shaun Gallagher – ‘enactivists’ who argue that human thought is not brainbound but stems from connections between the mind and body and its environment – to conclude, to varying degrees, that human perceptions are for the purpose of action. Sometimes, however, I just want to look at something, not reduce it to a tool.
Habits consolidate what control we can have of our passions. Hume gives habit pride of place in his moral accounting, but the key here is to continually assess whether we have the right habits, not to passively accept existing habits. ‘Nothing can be more laudable,’ he writes, ‘than to have a value for ourselves, where we really have qualities that are valuable.’ In other words, he asks for empirical evidence of value, not just for our feeling of it. Habits, after all, make it possible to contain violent passions such as anger. Hume insists that ‘when a passion has once become a settled principle of action, and is the predominant inclination of the soul, it commonly produces no longer any sensible agitation’. In this view, habit reduces passion’s agitations, making them manageable.
Hume’s idea that reason serves the passions has in important ways found scientific support. Our rationality serves our passions, and we have less control over the passions than is commonly presumed. By stipulating that reason is the slave of the passions, Hume warns us of the consequences of not having the right habits. When neuroscientists equate emotion and action, it narrows emotion to survival and underestimates the ways in which the emotions can foster deliberation. While neuroscientists set the timescale of the emotions to no more than a few minutes, Hume insists that it will take nothing less than a lifetime to get our emotions right.”