Philosophy of Memory
Memory is a subject amply covered in literature and science (especially psychology) but we hear little about it in philosophy. We find books on consciousness, perception, imagination, language, emotion, the will, and the unconscious: but I don’t recall ever seeing a philosophy book devoted to memory. Memory is the forgotten subject in the philosophy of mind.  Presumably it is felt that memory doesn’t present much in the way of philosophical food for thought; it doesn’t raise philosophical problems, or offer puzzles and paradoxes. Or possibly people just don’t know where to begin with it. Here I will outline the future subject of the philosophy of memory, expecting some recognition of what that field might contain. This will consist mainly of a series of questions.
Does memory give knowledge of the past? Is it a vehicle of genuine knowing? Does it provide knowledge of the past in the way perception provides knowledge of the present? Are there memory images? Are they like other types of mental image? Does memory involve belief—sometimes, always, never? Is it propositional? How is it connected to language—contingently, necessarily? What is its phenomenology? What is it like to remember? Does it have a phenomenology analogous to perception or to belief or to inner speech? How are memories connected with facts external to the remembering subject? Are they susceptible to Twin Earth cases? Are memories “in the head”?
Are there different types of memory? Are there different faculties of memory that have a modular organization? Are they encapsulated in Fodor’s sense? Does the Muller-Lyer illusion afflict memory? Does each sense have its own memory faculty? Is there such a thing as memory blindsight? How many types of memory faculty are there? Say short-term memory, long-term memory, echoic memory, iconic memory, factual memory, muscle (motor) memory, linguistic memory, experiential memory, and emotional memory: are these all completely different or are there common principles, overlapping codes, and functional universals? Is that list exhaustive or might we discover more types of memory? How fine-grained is the modularity? Do animals have types of memory alien to human memory? Do all species remember in fundamentally the same way?
What form do memories take? Presumably they are largely unconscious (unless being actively recalled), but what is this state of existence? Is it just a matter of brain states, so that we can be materialists about memories in their inactive form? Is there an unconscious language of memory like the (alleged) language of thought? Is memory like belief in being capable of both conscious and unconscious existence? Is it satisfactory to identify latent memories with dispositions to remember? Can there be memories that have no disposition to reach consciousness? Is memory, like language, a combinatorial system with infinite potential? Is it productive, creative, and cleverly computational? Does it have a “grammar”? Are there symbolic acts of memory? Is its notorious unreliability a result of its internal architecture (compare the structure of language)? Is its scope a liability?
Where does memory begin and end? Do worms remember (they can be conditioned)? Are tree rings a primitive form of memory? Does light remember its source? Are traces of the past nature’s form of memory? Did animal memory evolve from such physical phenomena? We apply the word “memory” very broadly, but does it extend beyond brains? Is DNA a type of memory? Is an organism a walking memory of its evolutionary history? Would it be illuminating to start talking this way? If we can talk fruitfully of selfish genes, can we fruitfully talk of remembering genes? Can we introduce the concept of the extended memo-type analogous to the extended phenotype? Are footprints and odors memories that exist outside the organism’s conventional boundaries? Is writing a type of memory? And how much of the mind is really a form of memory? Are perceptions memories of the stimuli that elicit them (the “sensory register”), these stimuli existing in the recent past (as measured in milliseconds)? Is an after-image a memory? Is memory essential to perceptual categorization? Can an organism perceive that has no faculty of memory? Is what we perceive really a world of memory? Isn’t everything we see and think steeped in the past? Is a concept actually a memory trace, possibly derived from earlier encounters with reality? Might we end up saying that everything has a bit of memory in it (“pan-memory-ism”)? The universe remembers its earlier states (or has “proto-memories” of them), so that memory is everywhere; and the mind is a general-purpose memory machine—perpetually digging up the past as it negotiates the present and anticipates the future? We might develop a metaphysic of memory according to which memory is written into everything. The world is not a collection of sensory ideas in the old idealist style but a collection of memories—remnants of the past containing information about it. This is idealism built around remembering not perceiving.
There seems more than enough here to occupy the philosophical student of memory. I envisage anthologies devoted to the many aspects of memory studies (Contemporary Essays on the Metaphysics of Memory, Whither Memory?, Remember!). After all, Proust wrote several hefty volumes on the subject of memory; the memoir is an established literary genre (e.g. Speak, Memory, by V. Nabokov); and everyone is obsessed with his or her memories: one would think the philosopher should pay more attention to the subject. Could it become the next philosophical fashion once consciousness has fizzled out (only to rise again in a hundred years)? It shouldn’t be left entirely up to the psychologist surely: maybe there are some juicy conceptual confusions to be ferreted out! At the least there are doctoral dissertations to be composed, conferences to be convened, and names to be made. It’s past time for memory to find its rightful place in the philosophical firmament. 
 My own interest in the topic of memory goes back to my days as a psychologist (circa 1970) when I used to do experiments on memory and found the subject infuriatingly fascinating (what are memories?). But the topic fell off the map for me when I went into philosophy where the subject is rarely mentioned.
 Old hands will remember “Remembering” by C.B. Martin and Max Deutscher, Philosophical Review (1966) in which a causal theory of remembering is proposed: but it’s hard to think of anything else that has made a comparable mark (unless my memory fails me). The philosophy of memory has languished since then.