In Moral Brains: The Neuroscience of Morality
Here is an excerpt:
What Is the Issue?
The question is basically whether morality is like memory. Once upon a time, philosophers and psychologists believed that memory is monolithic. Now memory is understood as a group of distinct phenomena that need to be studied separately (Tulving 2000). Memory includes not only semantic or declarative memory, such as remembering that a bat is a mammal, but also episodic memory, such as remembering seeing a bat yesterday. Memories can also be long-term or short-term (or working) memory, and procedural memory includes remembering how to do things, such as how to ride a bike.
Thus, there are many kinds of memory, and they are not unified by any common and distinctive feature. They are not even all about the past, since you can also remember timeless truths, such as that pi is 3.14159 …, and you can also remember that you have a meeting tomorrow, even if you do not remember setting up the meeting or even who set it up. These kinds of memory differ not only in their psychological profiles and functions but also in their neural basis, as shown by both fMRI and by patients, such as H. M., whose brain lesions left him with severely impaired episodic memory but largely intact procedural and semantic memory. Such findings led most experts to accept that memory
is not unified.
This recognition enabled progress. Neuroscientists could never find a neural basis for memory as such while they lumped together all kinds of memory. Psychologists could never formulate reliable generalizations about memory as long as they failed to distinguish kinds of memories. And philosophers could never settle how memory is justified if they conflated remembering facts and remembering how to ride a bicycle. Although these problems remain hard, progress became easier after recognizing that memory is not a single natural kind.
My thesis is that morality is like memory. Neither of them is unified, and admitting disunity makes progress possible in both areas. Moral neuroscience, psychology, and philosophy will become much more precise and productive if they give up the assumption that moral judgments all share a distinctive essence.
The book chapter is here.