As Descartes famously pointed out, the knowing subject can be sure of one thing – his or her own thoughts, the ideas that are the basis of conscious experience. I have thoughts or ideas, and – assuming that other people are like me in that regard – I expect others to also have ideas. This is certainly an assumption for as Descartes had deduced we cannot know whether our thoughts represent anything outside ourselves (an external world beyond our own selves), and even if we do accept the existence of the world and others inhabiting it, they could – as some philosophers have commented – be automata lacking mental experiences like our own.
Although such grounds for adopting solipsism may be strictly true in a logical sense, we generally accept that there is an external reality, and that what we perceive as an external world, and the people in it, are more than fi gments of our own imagination. It would be hard to imagine how life could be lived otherwise. So for the purpose of writing this book, and indeed, an essential assumption to make it worth my while setting out to write a book, I imagine my readers do have mental experiences, and that you will share my assumption that all humans experience thoughts and have ideas just as we do. So, here are some assumptions that are not absolutely logically secure, but ones I imagine most science educators will have no diffi culty accepting. So, here at least are some common commitments among colleagues working in the research programme! Most of us include such assumptions in our worldview, as taken-for-granted assumptions.
Figure 3.1 presents a very simple representation of the individual, considered as a thinker – having conscious thoughts – located in and acting in an external world.
The thinker, who I will call Jean, is an embodied person, inhabiting a body that is physically demarcated from the external world, that is, there is a fairly clear boundary between Jean and Jean’s surroundings. The space outside Jean has been labelled as a public space, as other thinking subjects (not shown in this fi gure) will also inhabit this same physical world.
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Mind and Matter
The simple structure of Fig. 3.1 ignores a major problem that will be of considerable importance in exploring research into student thinking. Conscious thought is considered to be in some sense located ‘within’ Jean as an individual. Thoughts are
‘internal’ mental experiences, so clearly they must occur ‘inside’ us. However, if we ask where these thoughts occur, we fi nd two common suggestions.
One is that mental activity takes place in the brain. There is certainly extremely strong scientifi c evidence to consider that our thoughts are related to electrical activity in parts of the brain, and that in terms of physical processes such as chemicals diffusing across synapses and electrical signals passing through networks of neurons, this is the location of thinking in the body. Arguably there is no absolute distinction between the brain and the rest of the nervous system, but it at least seems reasonable to consider that thinking is due to activity in the nervous system.
However, although it seems fairly clear that our thoughts are correlates of electrical activity in the nervous system, the thoughts themselves are subjective experiences that cannot be objectively (i.e. by any neutral observer) observed. There are a number of techniques that allow electrical activity in the brain to be investi- gated, some with good temporal resolution and some with good spatial resolution.
However, unlike in some science-fi ction scenarios, there is as yet no device that allows anyone to experience the thoughts of another. Indeed there are good reasons to suspect this could never happen.
The second suggestion for locating thoughts is inside our minds . Unlike the brain or central nervous system, the mind is not a physical entity. Rather the notion of the mind is a theoretical construct that has been found useful in a range of explanatory schemes (Claxton, 2005 ). People are minded to do certain things and are commonly
Fig. 3.1 The individual in the world
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said to have beautiful (or troubled, or diseased, or dirty, etc.) minds. In effect, the mind is the hypothetical ‘place’ where our mental lives occur, that is, ‘where’ we have subjective experiences (thoughts). Table 3.2 sets out a simple demarcation between mind and brain. The key point is that the mind, unlike the brain, is not a physical entity; it does not have physical form or material substance; it is immaterial.
Arguably the whole notion of mind is a kind of analogical model . In the physical world, objects have substance and are located somewhere. So we can understand our thoughts (by analogy with experience of the physical world) as being the (metaphorical) substance of our mental worlds, and so the mind may be considered as the (meta- phorical) container where we have ideas, or perhaps even the (metaphorical) factory where we produce them or the (metaphorical) home where they live, or the (metaphorical) theatre where they are played out, etc. Even referring to a mental
‘world’ would seem to be adopting an analogy with the physical world . According to Lakoff and Johnson ( 1980a ), all our concepts must ultimately be grounded in our experience of the material world, but this means that again the metaphors we adopt can come to be taken for granted: of course the mind is a place, what else could it be?
One of the key issues in philosophy, and indeed one source of the ‘big’ questions in science, is how mind and brain are related, that is:
• How can physical reality be experienced subjectively?
• How can our minds interact with matter to bring about actions in the physical world?
The fi rst question is clearly a genuine and potentially scientifi c question. For anyone who accepts the existence of an external physical reality, the question of how we can experience and know about that reality is a ‘big’ question, quite fundamental to understanding ourselves in the world.
Some would suggest that the second question is based on a false premise. We consider that our thoughts are somehow able to bring about changes in the world:
I would like some tea, so I intentionally go to the kettle. Certainly we perceive that we carry out physical actions such as fi lling the kettle with water and turning on the switch that seem to be necessary to bring about our plans to make a cup of tea.
Thought as an Epiphenomenon
However, it is logically quite possible that our thoughts are better understood as by- products of the physical processes occurring in the brain. That is, feeling thirsty is a perception of the body’s homeostasis system being triggered to bring about water intake. In principle it could be possible for the biological mechanisms to trigger
Table 3.2 The Mind-brain distinction
Domain Mental Physical
Location Mind Brain
Activity Thinking – having ideas Processing (chemical/electrical)
‘Substance’ Thought Matter
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processing in the brain that leads to my making a cup of tea without any need for conscious thought. This need not imply that making a cup of tea is not intelligent or learned, for my brain has built up neural circuits to allow my body to operate in my environment and carry out crucial actions – such as preparing tea. However, this physical system (based on chemical sensors and electrical signals) might well operate perfectly without my needing to have conscious thoughts about it. My being aware of thirst and ‘deciding’ to make a cup of tea could well be just a by-product of the process.
If this seems fanciful, it is worth noting that we often carry out many complex procedures without consciously directing them. It is common experience that we sometimes make mistakes because of this. We go straight home, or directly to work, instead of pausing at the postbox where we intended to post a letter, or heading off to a meeting in a less familiar location, because our minds were thinking about some- thing else, or our minds ‘were some where else’ as we sometimes say, whilst our body carried out our familiar patterns of action. Sleepwalkers seem capable of complex actions without conscious awareness: ‘some individuals have been known to drive cars for great distances whilst sleepwalking’ (Mahowald & Schenck, 2000 , p. 323).
This is a point that may seem more signifi cant to philosophers than science educators, as for most everyday purposes, we talk and behave as though people are making conscious decisions and behaving accordingly. At least since Freud, it has been widely accepted that we may not always be aware of our motives for certain actions (or inactions), but this tends to generally be considered as a secondary pathological effect impairing the normal state of things where we are in conscious control of our actions in the world.
However, this is in effect a ‘folk model’ based on common-sense understanding rather than scientifi c knowledge. The common acceptance of a folk model of mind that informs people’s ways of talking no more makes it scientifi cally correct than the common adoption of impetus-like notions (alternative conceptions) of force and motion. Most students believe that an object will only continue to move if it is subject to a continuous applied force; and similarly most teachers probably believe that the conscious mind controls behaviour.
However, what will be important for our analysis of what is going on in research into student thinking is the key point that mental life and the thoughts and subjective experiences people have are quite distinct in nature and ‘substance’ from what can be observed and measured by scientifi c observers, and in that sense, Fig. 3.1 may be misleading:
Mental events and externally observable (physical) events constitute two categorically separate kinds of phenomena. They are mutually irreducible categories in the sense that one cannot, a priori , be described in terms of the other. (Libet, 1996 , p. 98)
Figure 3.2 represents this by locating conscious thinking in a distinct ‘place’
within the individual, but in a part of the individual that is not within the public space.
The border around conscious thought in Fig. 3.2 is meant to represent how the mind is a distinct aspect of the individual from the physical body, although in some sense embodied. Figure 3.2 is only a schematic representation, and it is possible to
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read it a number of ways. It suggests the existence of the mind as a real entity, which is part of the person, but not part of the physical world. An obvious implication here would be the dualist one, that mind is of a different sort of stuff to matter, and somehow communicates with it.
This is somewhat problematic as if mind is thought of as something separate from the material world, then any consideration of its form is outside of the realm of science, and mind must interact with matter by mechanisms that are totally unknown to science. However, it will be suggested below that it is possible to retain the notion of mind as a useful concept, without adopting dualism.
The Problem with a Dualist Model of Mind
A key diffi culty in modelling a student’s idea, knowledge, learning, etc. from a dualist perspective is that one has to take one of two positions: either that mental thought can infl uence matter so that ideas in the nonmaterial mind are somehow then coded into physical form in the brain to be acted upon, or that conscious thinking is an epiphenomenon of brain processes, and that the subjective perception that we have some control over our actions through conscious thought is an illusion.
The former position fi ts better with the way people commonly understand and speak about the mind, but there is currently no known mechanism drawing upon established scientifi c principles which could explain how a nonmaterial mind could control our bodies. The second position, at least when expressed in the form above,
Fig. 3.2 A dualist representation: conscious thought as a distinct, non-physical, aspect of the individual (cf. Fig . 3.1 ) The Mind
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seems to suggest that we are just automatons responding to programming with an illusion of responsibility and control over our actions. This could be true but would likely be unwelcome. That it would be unwelcome would of course make it no less likely to be true! However, there is a different way of thinking about the brain-mind relationship.