There has been a great gulf in psychological thought between the perception of space and objects on one hand and the perception of meaning on the other.

What a thing is and what it means are not separate, the former being physical and the latter mental as we are accustomed to believe.

Psychology is still trying to explain the perception of the position of an object in space, along with its shape, size, and so on, and to understand the sensations of color.

I also assume that they are not simply the physical properties of things as now conceived by physical science. Instead, they are ecological, in the sense that they are properties of the environment relative to an animal.