[…] there is, I think, a great deal of difference between a concept and a percept, which tends to be obscured by loose ways of talking and thinking. We use “concept” for any kind of mental image. In fact, there are mental images of percepts and concepts. We might say, loosely, that I have a concept of the glass that is presently standing on my table, meaning, I can close my eyes and present myself with a mental image of my glass. That is a mental image of a percept, i.e., my glass as I perceived it now-empty, but for a small slice of lemon. Of course, I could imagine it completely empty-which is a percept of how it was at another time; or full-which is the same. However, I can also have a mental image of the category glass, which embraces my glass and all other glasses, and which is not a percept but a true concept.
- Bickerton (1981), a pag.221-222

Until a percept – the image of a particular entity on a particular occasion – can be replaced at will by a concept – the image of a class of entities, divorced from all particular instantiations of that class – then the power to predict is limited.
- Bickerton (1981), a pag.227

[…] concepts as distinct from percepts, do not exist in isolation. We do not delimit percepts in terms of percepts. I do not distinguish Aunt Emma’s face because it is bounded on one side by Aunt Mary’s face, on another by Cousin Emily’s face, and so on; nor (just to show that this fact has nothing to do with any heightened perception of conspecifics) do I distinguish my toothbrush because it is bounded on one side by my wife’s toothbrush, on another by my son’s toothbrush, etc. But I do distinguish deer because they are bounded by horses on one side, cattle on another side, and so on; I do distinguish toothbrushes in general because they are bounded by hairbrushes, nailbrushes, bootbrushes, etc. Deer stop where horses begin. Toothbrushes stop where nailbrushes begin. But Aunt Emma’s face does not stop where Cousin Emily’s face begins. That is the difference between percept and concept, class member and class. Concepts are delimited in terms of one another, percepts only in terms of themselves.
- Bickerton (1981), a pag.230-231

Concepts are like the counties on a state map, in several ways. Where one stops, another starts. Although each is composed of so many acres and contains so many individuals, none is merely the sum of the acres that compose it or the people who inhabit those acres. Each of them has its place with respect to others. The same with concepts. Percepts inhabit concepts, but concepts are not the sum of their percepts.
- Bickerton (1981), a pag.231

If percepts could be filed fractured, so to speak, concepts must be filed as gestalts.
- Bickerton (1981), a pag.232

[…] instead of the same set of neurons representing similar aspects of the images of quite different things, as we supposed was the case in the storage of percepts, separate sets of sets, involving heavy duplication of function, would be required for each network of neurons that represented a concept. If this were so, it would explain why, while percepts may be stored in literally infinite quantity, the list of concepts, or at least the list of primitive concepts, is certainly finite and probably quite short (of course, an infinite number of secondary concepts – timber wolf, prairie dog, etc. – can be constructed by combining two or more primitive concepts).
- Bickerton (1981), a pag.232

We saw that both creole speakers and children were able to distinguish with great ease between specific and non-specific (generic) reference. Now, if percepts – images of particular entities on particular occasions, therefore specific – and concepts – images of class of entities, therefore non-specific –are stored in different places and in different ways, this distinction would be built into the neuronal system.
- Bickerton (1981), a pag.234