Dear Noah,
   In contemplating morality questions, like the ones you are asking, I have
concluded that there is no absolute morality. Instead, what is considered
right and wrong depends on the social context. What is considered morally
wrong for an adult may be acceptable for a child. What is right in your
country might be unacceptable in another country.
   I am responding to your questions, whether mollusks feel pain and whether
they are sentient. In a way, you are asking if mollusks satisfy the criteria
for special status (in this case, for not being eaten, or not being harmed).
In response, I want to address whether sentience is a good criterion for
special status.
   All creatures, including mollusks, respond to stimuli. Without an
explicit, verifiable, universally accepted, and universally applicable
definition of feeling, I don't know how we could ever know whether other
species feel pain. Until you overcome this uncertainty, I don't think you
can validly use the ability to feel pain as a criterion for special status.
   A similar difficulty applies to the sentience question. There is no sharp
dividing line between sentience and non-sentience. Different people would
likely choose different dividing lines using sentient criteria. Note that if
you gave special status to individuals who are conscious or self-aware, you
would include at least some non-human species, but you would also exclude
some humans!
   Even if Mollusks were brainless (I myself do call their centralized
collection of ganglia a brain), you would need to establish that the
brain-bearing species deserve special status that the others don't. Note
that octopuses (mollusks) are probably the most intelligent non-vertebrates.
How could you establish that having a large brain, or an arbitrary
intelligence level deserves special status, except by decree? Are we
choosing big brains, or intelligence, or sentience as the membership card
for this club simply because we humans possess those characteristics? If
other species were to choose the criteria for special status, might they
choose good ability to detect odors (as most species do), ability to
communicate by changing skin color (as many cephalopods do), or being
hermaphrodite (as many mollusks are)?
   Life today requires interacting with other individuals. Humans regularly
kill plants and animals for food, clothing, and for enjoyment such as
ornaments and shell collecting. Some people behave respectfully to other
species in a modified Golden Rule: do unto other species as you would have
other humans do unto you. If the way we interact with other species reflects
how we interact with other humans, then I would prefer to be around humans
who are compassionate and respectful to other species.
   We all must choose how we will interact with our universe. Most people
don't think about it. I applaud you for contemplating how you interact with
other creatures.
   -Tim-

Timothy A. Pearce, Ph.D., Curator of Mollusks
Carnegie Museum of Natural History
4400 Forbes Ave, Pittsburgh, PA 15213-4080
phone: 412-622-1916; fax: 412-622-8837
email: [log in to unmask]