A statue of David Hume sits in front of St Giles Cathedral in Hume's hometown, Edinburgh. (Richard Croft)
With all this talk about justice and rationality in ethics, what should we say about the role of passion? David Hume, a moral sentimentalist, firmly believed morality couldn’t be defined without it. Morality, he said, can’t be boiled down to external or objective facts, discoverable through reason or other modes of representation. Instead, morality is something found within us, whereby our moral sense—our response to our perception of things—allows us to define right and wrong, not empty legalities.
Why did Hume think this? To understand his position we first need to consider his ‘science of man’, which focuses on our perceptions of things and their relations. To him our perceptions come in two forms: impressions (sensations, desires, passions, emotions) and ideas (copies and combinations of impressions). With this philosophy-of-mind strategy, Hume built a desire-based theory of ethics, wherein the foundations of moral beliefs are born in impressions.
Reason alone, he thought, cannot determine a moral action but our passions can. So while it’s unreasonable of me to prefer the destruction of the whole world to the scratching of my finger, it’s only immoral if I assign value to human life. Hence what we value defines the morality of our actions; and what we value is born in our experience of the world through our impressions and ideas.
What do you think?