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are not thought of as isolated units ; they form 

 parts of the syntax, and thus the syntax itself is also 

 projected, and is looked on as part of an external 

 world. My own idea is that this extern alisation 

 always occurs when a syntax passes into action 

 without conscious hesitation ; the hesitation being 

 a sign that the syntax has not yet been repeated 

 so often as to form a fully established track among 

 the nervous connections. Certainly the fact that 

 externality is attributed to a particular syntax does 

 not establish it as an unquestionable truth. The 

 Ptolemaic astronomers of many centuries attributed 

 external existence to the immovable earth which 

 formed the centre of their system ; the Newtonians 

 to the corpuscles which conveyed light from a 

 luminous body to the eye ; men of science, before 

 Rumford, to the imponderable fluid which they 

 called caloric : yet none of them are in any sense 

 true for us. 



