During the sixties and seventies, we heard a good deal about something called “psychological reality”, although what it was was never well defined; I would suggest that whatever the fate of the theory argued here, any future linguistic theory will have to be able to claim “biological reality” if it is to be taken seriously. The theory argued here has claimed that many of the prerequisites for human language were laid down in the course of mammalian evolution, and that the most critical of those prerequisites – for even things like vocal tract development, but in no sense sufficient, requirements – was the capacity to construct quite elaborate mental representations of the external world in terms of concepts rather than percepts. In other words, something recognizable as thought (though clearly far more primitive than developed human thought) necessarily preceded the earliest forms of anything recognizable as language.
- Bickerton (1981), a pag.294-295