The Emotion Machine

Logic and the seemingly similar chainlike forms of everyday commonsense reasoning. We all know that a physical chain is only as strong as its weakest link. But long mental chains are flimsier yet, because they keep growing weaker with every new link!

So using Logic is somewhat like walking a plank; it assumes that each separate step is correct—whereas commonsense thinking demands more support; one must add evidence after every few steps. And those frailties grow exponentially with increasingly longer chains, because every additional inference-step may give the chain more ways to break. This is why, when people present their arguments, they frequently interrupt themselves to add more evidence or analogies; they sense the need to further support the present step before they proceed to the next one.

Envisioning long chains of actions is only one way to deliberate—and chapter §7 will discuss a good many more. I suspect that when we face problems in every day life, we tend to apply several different techniques, understanding that each may have some flaws. But because they each have different faults, we may be able to combine them in ways that still can exploit their remaining strengths.

Every person accumulates many ways to make short-range plans, to compare the options open to us, and to apply our usual methods of reasoning—and we usually do this so fluently that we’re scarcely aware of doing it. However, when those processes fail, and we need to replace our present techniques—then we start thinking about what we’ve been doing—and that’s what we call reflective thought.

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§5-4. Reflective Thinking

I am about to repeat a psalm that I know. Before I begin, my attention encompasses the whole, but once I have begun, as much of it as becomes past while I speak is still stretched out in my memory. The span of my action is divided between my memory, which contains what I have repeated, and my expectation, which contains what I am about to repeat. Yet my attention is continually present with me, and through it what was future is carried over so that it becomes past.

Augustine, in Confessions XXVIII

When Joan first perceived that approaching car, that emergency got her full attention— but now that she has more time to think, she can think about what she’s recently done and reflect on her recent decisions and actions, as in,

Joan reflects on her hasty decision.

To do this, Joan must recollect some aspects of her previous thoughts, as though she could go back in time, and think about what she was thinking then. But how could she manage to do such a thing? From a commonsense view, that’s no problem at all: just remember those thoughts and then think about them. But when we ask how that might actually work, we see that it needs some machinery like the kind we depicted in §4-8, in which resources at each level make descriptions of what some lower-level ones recently did.

In any case, there is nothing strange about detecting events inside the brain. Most of our brain-parts already do this; only a few of them have external connections, like those that get signals from eyes or skin, or those send messages to your limbs. Furthermore, it could have been far easier to evolve resources that detect events in newly developed parts of our brain (like those in the deliberative level) than to evolve new resources that discern events in the outside world—because our sensory systems are more complex (from evolving for hundreds of millions of years).

How could we design a machine to reflect on its own activities? Could just adding one more ‘cognitive layer’ result in such a profound improvement? Indeed it could—because reflecting on your recent thoughts could use some of the same sorts of processes that you already use for deliberating about your observations of recent external events. For example, Joan might recall the choice she made, and reconsider how she made it.

I decided that being late would be worse than the risk of being hit by that car, because that would normally be improbable. But that choice was wrong because my injured knee had decreased my agility, so I should have changed my priorities.

What some of brain events should reflections detect? That would include predictions that turned out to be wrong, plans that encountered obstacles, or failures to access the knowledge you need. How should you to react to these? We’ll discuss this at length in Chapter 7.

Student: Would we want to say ‘conscious’ for such a machine? It includes most of the features you mentioned in §4-1, namely, short-term memory, serial processing, high-level descriptions. It only lacks models of itself.

The better some parts of a brain can reflect on what happens in various other parts of it, the greater will be the extent to which it can ‘think about’ the things that happens inside itself. However until it has models that represent such events on larger scales, the machine won’t have any overall views of itself as a self-aware entity. However, it never would be practical for a system to see all the details of itself at once—so when we discuss this in Chapter §9 we will have to conclude that anything like a human mind will need to make, not a single ‘unified’ model, but a variety of incomplete ones, each of which tries to represent only certain aspects of what the whole system does.

§5-5. Self-Reflection

“Another of the great capacities in which man has been said to differ fundamentally from the animal is that of possessing self-consciousness or reflective knowledge of himself as a thinker … [whereas the animal] never reflects on himself as a thinker, because he has never clearly dissociated, in the full concrete act of thought, the element of the thing thought of and the operation by which he thinks it.”

—William James[77]

The reflective systems we just described can think about some of their recent deliberations. Self-reflection does just a little more: it considers not only its recent thoughts, but also the entity that had those thoughts. For example, when Joan thinks about herself as in,