If the HOT-account [i.e., the higher-order thought account -EA] of phenomenal consciousness were correct and if animals lacked the capacity for HOTs, then animals would be incapable of experiencing pain. . . Are we justified in rejecting the HOT-account of phenomenal consciousness, i.e., do we have evidence that the HOT-account is false? The answer is "Yes." First, we have reason to think that the HOT-account of phenomenal consciousness is false when applied to humans, because human infants and severely retarded human beings experience (morally significant) pain, even though they aren't capable of forming HOTs.
We also have independent evidence that many animals are capable of experiencing pain, evidence that parallels the evidence we have for thinking our fellow humans are capable of feeling pain: We witness pain behavior, not just reflex actions to noxious stimuli (protective pain), but subsequent pain-induced behavioral modification caused by bodily damage (restorative pain); we observe significant anatomical and neurophysiological similarity between humans and many animals (including all mammals and most vertebrates); endogenous serotonergic and opioid pain-control mechanisms are present in all mammals (Why would organisms incapable of feeling pain have endogenous pain-control systems?); efferent and afferent nerves run throughout their bodies; analgesics and anesthetics stop animals from exhibiting pain behavior, presumably because these substances prevent the pain itself in much the way they prevent pain in humans; and there is compelling experimental evidence that the capacity to feel pain enhances survival value in animals, based on the self-destructive tendencies displayed by animals that have been surgically deafferented. Based on this cumulative observational, analogical, and experimental evidence, we are clearly justified in accepting that animals can feel pain, and so, we're justified in rejecting any neo-Cartesian explanation that denies animals have this ability, based on what we justifiably accept. Consequently, all neo-Cartesian CDs fail, for they fail to meet even the low bar that Murray sets for CD-success. Neo-Cartesian CDs are not "as plausible as not, overall" given our justified acceptances.
NDPR Nature Red in Tooth and Claw: Theism and the Problem of Animal Suffering.