But for now, let's check out Sloman's view of free will as scalar rather than Boolean.
Section: Free Will à la Sloman
I'm rather taken with Sloman's notions about free will (1988). But how do I justify
bringing up the freewill issue in a chapter entitled "The Nature of Mind and the
Mind-Body Problem"? Well, we've just talked about an agent creating information
according to its needs and goals. What if there are goal conflicts? Does our agent
exercise free will? That's one connection. Recall that the central issue, always, for
a mind is how to do the right thing. Does a mind exercise free will in deciding what
is the right thing to do? That's second connection.
But all this is rationalization. Sloman disposes of the freewill problem by showing
it to be a pseudoproblem. He refocuses our attention away from the question "Does
this agent have free will or not?" by exposing us to all sorts of degrees of free
will. I want to convince you that it will be useful to think of all sorts of degrees
of having mind, of all sorts of degrees of having consciousness. I hope Sloman's
approach to free will serve as a formal analogy.
Sloman maintains that the basic assumption behind much of the discussion of free will
is the assertion that "(A) there is a well-defined distinction between systems whose
choices are free and those which are not." However, he says,
...if you start examining possible designs for intelligent systems IN GREAT DETAILThe deep technical question, he says, that lurks behind the discussion of free will
you find that there is no one such distinction. Instead there are many "lesser"
distinctions corresponding to design decisions that a robot engineer might or
might not take--and in many cases it is likely that biological evolution tried
Design distinction 1
Compare an agent that can simultaneously store and compare different motives as
opposed to an agent that has only one motive at a time I would say that the first
exercises more free will than the second.
Design distinction 2
Compare Artificial Minds agents all of whose motives are generated by a single top
level goal (e.g., "win this game"), with agents with several independent sources of
motivation (e.g., thirst, sex, curiosity, political ambition, aesthetic preferences,
etc.). If you're designing an autonomous agent, say a Mars explorer, here's a design
decision you have to make. Will you design in only one top-level goal, or will you
create several independent ones? If you choose the second, I'd say you must build in
more free will. This is going to get tiresome after a while because there are lots of
these design distinctions. But that's Sloman's point! I have to show you lots of
them, or you may miss it. Just skip ahead when you feel convinced.
Design distinction 3
Contrast an agent whose development includes modification of its motive generators in
the light of experience, with an agent whose generators and comparators are fixed for
life (presumably the case for many animals).
Design distinction 4
Contrast an agent whose generators change under the influence of genetically
determined factors (e.g., puberty), as opposed to an agent for whom they can change
only in the light of interactions with the environment and inferences drawn
therefrom. In this case, I couldn't say which one exercises more free will. It's not
much of an issue any more. The issue dissolves as we focus on whether to design in a
certain decisionmaking property. And I think the issues of what has mind and what
doesn't, or what's conscious and what's not, are going to dissolve in the same way
when we get down to designing mechanisms of minds.
Design distinction 5
Contrast an agent whose motive generators and comparators are themselves accessible
to explicit internal scrutiny, analysis and change, with an agent for which all the
changes in motive generators and comparators are merely uncontrolled side effects of
other processes, such as addictions, habituations, and so on. In the first case we
have an agent that not only can change its motive generators but also can change them
consciously. That seems like quite a lot of free will.
Design distinction 6
Contrast an agent preprogrammed to have motive generators and comparators change
under the influence of likes and dislikes, or approval and disapproval, of other
agents, and an agent that is only influenced by how things affect it. The agent has
some social awareness. There's much more to designing agents than just the pseudo
issue of free will.
Design distinction 7
Compare agents that are able to extend the formalisms they use for thinking about the
environment and their methods of dealing with it (like human beings), and agents that
are not. (most other animals?) Agents that can think about their paradigms and change
them would seem to have a lot more free will.
Design distinction 8
Compare agents that are able to assess the merits of different inconsistent motives
(desires, wishes, ideals, etc.) and then decide which (if any) to act on, with (b)
agents that are always controlled by the most recently generated motive (like very
young children? Some animals?).
Design distinction 9
Compare agents with a monolithic hierarchical computational architecture where
subprocesses cannot acquire any motives (goals) except via their "superiors," with
only one top-level executive process generating all the goals driving lower-level
systems, with agents where individual subsystems can generate independent goals. In
case (b) we can distinguish many subcases, such as (b.1) the system is hierarchical
and subsystems can pursue their independent goals if they don't conflict with the
goals of their superiors (b.2) there are procedures whereby subsystems can
(sometimes?) override their superiors. [e.g., reflexes?]
Design distinction 10
Compare a system in which all the decisions among competing goals and sub-goals are
taken on some kind of "democratic" voting basis or a numerical summation or
comparison of some kind (a kind of vector addition, perhaps), with a system in which
conflicts are resolved on the basis of qualitative rules, which are themselves partly
there from birth and partly the product of a complex high-level learning system.
Here we have the distinction between connectionist systems (a) and symbolic AI
systems (b). This distinction will occupy us during a later stop on our tour. Surely
you've gotten the point by now and we can stop with ten examples, although Sloman did
It's a strange kind of argument. Sloman argues against free will not directly but by
pointing out that free will is based on the assumption of a sharp distinction. He
then says that if you look closely enough, you don't find this sharp distinction. The
whole idea is to point out that free will is really a nonissue, that these specific
design distinctions are the important issues. He's essentially taking the engineer's
point of view rather than the philosopher's, even though he is a philosopher. When we
explore the fascinating space of possible designs for agents, the question of which
of the various systems has free will becomes less interesting.
Design decisions are much more fascinating.
Degrees of Mind
As we begin to make specific design distinctions concerning aspects of mind other
than control, the question of mind attribution should dissolve as the freewill
question did. Here are a few such distinctions couched in the style of Sloman. Note
that all of them could and should be refined into finer distinctions, and that some
of them may well turn out to be spurious.
Design distinction S1
Compare an agent with several sense modalities, with (b) an agent with only one sense
(e.g., a thermostat).
Design distinction S2
Compare an agent only one of whose senses can be brought to bear on any given
situation (e.g., a bacterium [?])., with an agent who can fuse multiple senses on a
single object, event or situation.
Design distinction M1
Compare an agent with memory of past events, with an agent without memory. Does a
thermostat have memory? It certainly occupies one of two states at a given time. One
might claim that it remembers what state it's in. Allowing memory in such a broad
sense makes it difficult to imagine any agent without memory. This distinction should
be taken to mean memory in some representational sense, perhaps the ability to
re-create a representation of the event.
Design distinction M2
Compare an agent with short- and long-term memory, with an agent with only short-term
memory. Do insects have only short-term memory for events, or can some of them recall
the distant past?
Design distinction M3
Compare an agent that can add to its long-term memory (learn?), with an agent that
cannot (e.g., some brain-damaged humans). I can imagine wanting to design an agent
that remembers during its development period but not thereafter. An analogous
situation is a human child's ability to learn a new language easily until a certain
age and with more difficulty thereafter.
Design distinction M4
Compare an agent that can store sensory information from all its modalities, with an
agent that can store sensory information from only some of them. I think some of
Rodney Brooks's robots satisfy (b), at least for brief periods (1990c). His work will
occupy a stop on our tour.
Design distinction T1
Compare an agent that can operate only in real time, with an agent that can plan.
This is a graphic example of a coarse distinction that could be refined, probably
through several levels. The ability to plan can range from a dog walking around an
obstacle to get to food on the other side to a complex chess stratagem involving ten
or more moves of each player.
Design distinction T2
Compare an agent that can ''visualize" in all sensory modalities, with an agent that
can "visualize" in none, with an agent that can visualize in some but not others. I,
for instance, can easily conjure up a mental image of my living room, but I cannot
"hear" a melody in my head or imagine the smell of popcorn. Note that this is not
simply a lack of memory for music or smells. I can readily recognize familiar
melodies on hearing them, and familiar odors as well.
Design distinction T3
Compare an agent that can create mental models of its environment, with an agent that
cannot The utility of mental models is a hotly debated issue just now, in the guise
of "to represent or not." We'll visit this topic toward the end of our tour. Also, we
have here another obvious candidate for refinement. There are surely many degrees to
which an agent could create mental models, mediated by sensory modalities, type and
capacity of available memory, so on. Could we say that agents with some of these
abilities display a greater degree of mind than the counterpart with which they were
compared? I think so. Surely it takes more mind to plan than to act, if only because
planning--for an agent, not a planner-- presumes acting. Thinking of mind as a matter
of degree may well make the task of synthesizing mind seem less formidable.
We can start with simple minds and work our way up. I expect a real understanding of
the nature of mind to arise only as we explore and design mechanisms of mind. Let me
remind you of a quote you've already seen in Chapter 1 by way of driving home the
point: "If we really understand a system we will be able to build it. Conversely, we
can be sure that we do not fully understand the system until we have synthesized and
demonstrated a working model" (Mead 1989, p. 8). The next stop on the tour is
zoology, the animal kingdom. If we're to find minds and their mechanisms in other
than humans, surely that's the first place to look.
End Notes from Chapter 2 Relevant to discussion of Sloman
(From note 12)
12. Computer scientists speak of a Boolean variable, or just Boolean, as one that
assumes only two values, usually 0 and 1. A scalar variable, or scalar, assumes one
of some finite set of values.
13. Minsky, in his Society of Mind (1985), uses "agent" to refer to a mental process
with a certain amount of autonomy and some particular competence.
14. Not everyone will agree. Bob Sweeney comments as follows: "Free will has as much
to do with the issues of accountability, ethics and 'sin'. These cannot be glossed
over by reductionist arguments about design features."
15. I'm indebted to Dan Jones for this observation. (Written by Franklin)
Sloman, Aaron, 1998
"Disposing of the free will issue"
Posted to internet Connectionist List, June 19 1988.
Expanded version available online
Additional notes from Franklin's Chapter 2: