The first grows out of our perceptions of the world and consists of our thinking about things that we perceive and sense, not only in the physical world, but in our own mental world of meaning. By reflection and by the use of increasingly sophisticated language, we can focus on aspects of our sensory experience that enable us to envisage conceptions that no longer exist in the world outside, such as a ‘line’ that is ‘perfectly straight’. I now term this world the ‘conceptual-embodied world’ or ‘embodied world’ for short.
This is not the same as the notion of ‘embodiment’ in authors such as Lakoff, who focuses on all kinds of embodiment, including conceptual—which refers to conceiving concepts in visuo-spatial ways—and functional, in terms of the (possibly unconscious) ways of operating using human abilities as biological individuals. Lakoff and his colleagues assert, in their own broad meaning, that everything is embodied (Lakoff & Johnson, 1999, Lakoff & Nunez 2000). This is fine to make a point (that mathematics arises from biological human activity) but a classification with only one class is hardly helpful to analyse the nature of mathematical cognition. Instead I focus more on the notion of conceptual embodiment, which relates to the way in which we build more sophisticated notions from sensory experiences.
By formulating the embodied world in this way, it includes not only our mental perceptions of real-world objects, but also our internal conceptions that involve visuospatial imagery. It therefore applies not only the conceptual development of Euclidean geometry but also other geometries that can be conceptually embodied such as non-Euclidean geometries that can be imagined visuo-spatially on surfaces other than flat Euclidean planes and any other mathematical concept that is conceived in visuo- spatial and other sensory ways.