vital factor of (internal) drive and the primacy of the self-paced 

 probing mechanism. 



Let me enlarge upon that. The idea that thought is merely internal 

 simulation of our interactions with our surroundings is rather ob- 

 vious. One could even ask what else could it possibly be! But it 

 would be fallacious to conclude, as Hesslow (1994) appears to do, 

 that such simulations became possible when the system merely 

 learned to internalize processes that had until then been purely ex- 

 ternal. That would permit the bizarre possibility that there had been 

 pre-conscious speech, for example. The view I'm expressing here is 

 diametrically opposite. It says that the novel-schemata-acquiring and 

 novel-schemata-using faculties — including speech — which provide 

 consciousness with its decisive advantage were not possible until 

 evolution had produced just the right type of neural circuitry. The 

 word just is important here. It seems highly unlikely that complexity 

 of the type shown in figure 2 could have arisen without there having 

 been simpler precursors. And there is much evidence that this was 

 the case. The prediction-mediating cerebellum, for example, is seen 

 in relatively primitive creatures which are unlikely to possess con- 

 sciousness. And efference-copy feedback loops were invoked by 

 Erich von Hoist ( 1957) for the somewhat prosaic job of correcting 

 for retinal slip when the eye and the head are moving simultaneous- 

 ly, this servo mechanism being envisaged to function unconsciously. 

 I believe the vital evolutionary step was establishment of new con- 

 nections between brain components that already existed, and which 

 were already serving other less sophisticated tasks. (The high degree 

 of cooperativity required between different brain components, if 

 consciousness is to be possible, is emphasised in the views ex- 

 pressed by James Houk (1989) and more recently by Peter Gilbert 

 (2001 ).) When those new links appeared, the brain acquired its pre- 

 sent capacity for covertly running internal simulations of what it 

 was simultaneously achieving through its overt and unconscious 

 muscular activations. When that happened, consciousness had ar- 

 rived on the scene! 



Evolution, Novel Context-Specific Reflexes and Dreaming 



But what is the evolutionary advantage of consciousness? What 

 role does it actually play? Why could a non-conscious but otherwise 



19 



