Vincent Torley is a philosopher who posts at Uncommon Descent. He has an important post on my recent series of posts (here, here, here, here, here, here) on the concept of storage of memories in the brain and on artificial intelligence. I am grateful for his insights.

Dr. Torley:

Dr. Egnor is making two claims here: first, that memory is a kind of knowledge (namely, retained knowledge); and second, that knowledge is inherently propositional. In his reply, Dr. Novella objects to this definition:

Memories don’t have to be true, and they don’t have to be propositions. You can remember an image, a sound, an idea (true or false), an association, a feeling, facts, and skills, including specific motor tasks.

A far more accurate and useful definition of memory would be stored information.

It seems to me that Dr. Novella has a valid point here. Professor Robert Feldmann, the author of a leading psychology textbook… defines memory as "the process whereby we encode, store, and retrieve information" (Chapter 20, p. 209). That’s a fairly standard definition.

As Dr. Novella remarks, memory comes in many different varieties. In their article "The Role of Consciousness in Memory" in the online journal Brains, Minds and Media (July 4, 2005), Franklin, Baars, Ramamurthy, and Ventura distinguish several kinds of human memory systems. In their classification scheme…

In my posts I argued that much of neuroscience is conceptually confused, so quotation from several neuroscience sources does little to address the points I raised. They are just more examples of conceptual confusion.

First, I’ll address the question as to whether memory is inherently propositional. I asserted that memory is retained knowledge, and that knowledge is the set of true propositions. To be informed is to know — the derivation of "in-form-ation" is Aristotelian, referring to the process (-ation) of grasping the intelligible species (form) of an object by (in) the intellect. In this view, memory is a kind of knowledge, and knowledge is inherently the grasping of truth.

Dr. Torley is correct to point out that memory is not necessarily propositional. We have memories of perceptions and images as well as concepts. Of course perceptions and images aren’t propositions. But in each of these kinds of memory the knowledge remembered is true or real. I remember a scene I saw or a scene I imagined or a concept drawn from a scene. In each case, my memory is of something true or real, in the sense that if it wasn’t a scene I saw or a scene I imagined or a concept I had then it’s a mistake or a hallucination or a delusion, not a memory.

Cognitive neuroscientists tend to divide memory into declarative memory and non-declarative memory. Declarative memory is what we usually mean by memory of perceptions and images and concepts — declarative memory is memory that something is the case. Non-declarative memory is what we usually mean by the acquisition of a skill — the memory of how to ride a bike.

Some neuroscientists and philosophers who are critical of the conceptual landscape in neuroscience believe that non-declarative memory is really a kind of conditioning and is not memory in any meaningful sense. A worm that is conditioned to respond to a stimulus or a rat that finds cheese in a maze or a person who acquires the ability to ride a bicycle can hardly be understood to have the same ability that a person invokes to remember a fact. Conditioning is conditioning, and memory is memory, and attribution of conditioned responses — whether withdrawing from a stimulus or finding cheese in a maze or riding a bicycle — to memory of perceptions or images or concepts muddles our understanding of memory proper, which is declarative memory. A person with amnesia, for example, doesn’t forget how to walk or ride a bike. Conditioned reflexes aren’t memories, they’re conditioned reflexes. This is of course a controversial view, but it is, in my opinion, the correct one.

Furthermore, I believe that to assert that (declarative) memory can be false is to confuse memory with belief.

Memory, per se, can’t be false. If you ask me to remember to buy milk at the store, and then I come home with juice instead because I forgot your request and believed you asked for juice, then I didn’t remember what you asked me.

If you thought that your wedding anniversary was April 1 when it was really March 1, when you bring your wife flowers on April 1 it will do you no good to insist that you really remembered your anniversary because memories can be false. The fact is that you didn’t remember your anniversary.

Of course you might say that misremembering is a separate thing from not remembering at all. You might say that if you forgot your anniversary entirely, that would not be remembering, but if you have a faulty "memory," it’s still memory, just a mistaken memory.

But the concept that memory can be false has unacceptable consequences. If you take a history exam on the Revolutionary War and you get all of the dates and events and characters wrong, it would be to no avail to say to your professor that your memory of the Revolutionary War was perfect, because memories don’t have to be true.

So what kind of thought is it when we bring our wife anniversary flowers on the wrong day, or write on the exam that the Declaration of Independence was signed in 1777, if it is not memory? These errors are false beliefs, not memories of any sort.

Obviously we can hold beliefs about things in the past that are untrue. But those are untrue beliefs, not memories of anything.

Memory is retained knowledge. To have knowledge is to be in-formed — to grasp true beliefs or real perceptions or real images.

But you may ask: Isn’t false belief itself a form of knowledge?

This confuses knowledge with belief. My beliefs do not necessarily correspond to truth. But my knowledge must correspond to truth; it makes no sense to call a belief "knowledge" if it’s not true.

If my knowledge need not be true, then I can claim complete knowledge of all topics. Do I have complete knowledge of integral calculus? Sure I do! I have either true or false beliefs about any question I can be asked about integral calculus. Do you want to know the indefinite integral of (sinx cosx tanx cscx) dx? My answer: the square root of purple. If knowledge includes false belief, then I know the integral of (sinx cosx tanx cscx) dx as well as my calculus professor knows the integral of (sinx cosx tanx cscx) dx.

Obviously, true belief is knowledge in a way that false belief is not.

Let’s imagine a child taking a test on the multiplication tables. He gets a zero on the test, because he got all of the answers wrong. He goes to his teacher and insists that he deserves a 100 on the test. "I know as much about multiplication tables as you do, Mr. Smith," says the little boy. "For every question I was asked, I know either a true or false answer, just like you. Both true and false answers are knowledge just the same. So my knowledge of multiplication tables is perfect, like yours. Change my grade!"

Knowledge is not the set of all belief — it is a subset of belief. Knowledge is necessarily true belief, or it is meaningless.

Memory is retention of knowledge, and as such memory is necessarily the retention of true beliefs (in the case of propositional knowledge) or real perceptions and mental images (in the case of perceptions and images).

My plea is for conceptual hygiene in neuroscience. The assertion that memories and knowledge can be false beliefs (and that the brain stores memories and that the brain has representations of concepts) does a disservice to understanding. Concepts are prior to experiment. Our experiments are predicated on concepts. We can make no real progress in understanding the mind while we hold to concepts that are nonsense.

The reasons for modern conceptual confusions in philosophy of the mind and neuroscience may be found in the abandonment of hylemorphic (Aristotelian-Thomist) metaphysics in the 16th century, and its replacement with Mechanical Philosophy, which is the view that men are machines of a sort.

There is more to say about Dr. Torley’s replies to my views on storage of memories and artificial intelligence. These are important matters in our effort to understand the mind and the brain.

Image source: luke chan/Flickr.