Block’s Biological Reductionism

Philosopher Ned Block represents a majority of philosophers (and a large majority of scientists) who hold that “phenomenal consciousness is reducible to its physical basis” (Block, 2023, p. 445; Block, 2007). The best candidates for this reduction, he says, involve neurobiology. “For example, in the creatures that seem to have consciousness (e.g., primates, octopi), neurons operate via electrical signals triggering the release of neurotransmitters, and the neurotransmitters in turn engender further electrical signals. Neurons operate in a chemical soup, with direct effects from one neuron to another mediated by chemicals. The release of chemicals is not confined to the synapse but can also happen in dendrites” (Block, 2023, p. 446).

These propagating neurophysiological sparks and diffusing neurochemical transmitters compose a magnificently complex and integrated system that carries and conveys meaning. Block appeals to “this electrochemical nature of known cases of consciousness as an example of a candidate for neurobiological reduction of consciousness.”

To Block, “the border between seeing and thinking” provides insight into consciousness and helps adjudicate best theories (Block, 2023). He highlights this “joint in nature” between perception and cognition and advocates its study for demystifying the mind. He argues against theories of consciousness that focus on prefrontal cortex, arguing that perceptual consciousness does not require cognitive processing.