"Langue and parole"

What do experts say on the relationship between language and thought?

For getting some information about first 


theories of that relation we have to go a lot of 


centuries back, specifically to the greeks. Plato had the "theory of forms" in which the idea of thought and language having meaning as stemming from abstract definitions or concepts called “forms” and which all the “entities and qualities designated thereby can be subsumed”
Similarly John Locke of a more recent time describes the relationship between reality and language: Our senses, conversant about 


particular sensible object, do convey into the mind several distinct perceptions
 of things according to those various ways wherein those objects affect them.  
And thus we come by those ideas we have of yellow, white, heat, cold, soft, 
hard, bitter, sweet and all those which we call sensible qualities; which when I 
say the senses convey into the mind, I mean, they from external objects 


convey into the mind what produces those perceptions.


Source: http://www.ttt.org/linglinks/StacyPhipps.htm