The Cookie cutter paradigm is the following set of notions:

The first item may be further decomposed:

The reasons why these statements seem virtually self-evident — and have been so treated for most of the history of occidental metaphysics — are  psychological and neurobiological in nature.

If we look at a uniformly colored and evenly lit surface, it might seem to us that we perceive each part of this surface separately (to the extent that our visual acuity allows to resolve it) and that these separate perceptions make up the perceived surface. Nothing could be further from the truth. The bulk of the sensory data received and processed by the visual cortex concern discontinuities in the visual field (the optical images on the two retinas). The visual cortex is "interested" chiefly in

With the help of this information, the visual cortex (or that part of our mind which correlates with the visual cortex) constructs the visual world. The uniformly colored and evenly lit regions within the boundaries are filled in by it (much like children's coloring books) as determined by the changes that occur across boundaries.

Here is a well-known demonstration of the filling-in of uniform areas of the visual field. Shut your left eye, and look at the pink area below. Fix your gaze on the small circle. If the cross hasn't disappeared, vary your viewing distance until it does, keeping your eye fixed on the circle. The cross disappears because its optical image falls on the blind spot, a part of your retina that lacks light-sensitive cells. No visual information reaches your brain from this area, yet you do not see nothing. You see pink.

Now make the same experiment with the light blue area below. Again you do not see nothing. Where the cross ought to be, you see a light blue.

In the primary visual cortex (V1), most cells are orientation selective. The rest have center-surround receptive fields and are color selective.

The receptive field of a neuron is the retinal area from which input is received by the neuron. A center-surround receptive field is divided into a small center and a larger surround. Some neurons with such receptive fields are excited (their firing rate is increased) by illumination of the center and inhibited (their firing rate is decreased) by illumination of the surround; others are inhibited from the center and excited from the surround. None are excited if their receptive fields are uniformly lit.

Orientation selective neurons respond best to lines of a particular orientation — bright lines on a dark background, dark lines on a bright background, or boundaries between areas of different color and/or brightness. Some have small receptive fields and are sensitive to position. Others have large receptive fields, are much less sensitive to position, but respond selectively to a line's direction and speed of motion across the visual field.

In V1, 10 to 20 percent of the orientation selective cells are end-stopped, responding to short but not long line or edge stimuli. Further downstream, in visual area 2, at least half of the orientation selective cells are end-stopped. Since all visual information flows through these cortical regions, it is clear that line segments and outlines play a crucial part in the construction of the visual world. Neuroscientific studies have made it eminently plausible that the construction of the visual world involves a three-step synthesis:

So bent on constructing a world of bounded, 3-dimensional objects our minds/brains are that they "see" complete outlines where manifestly there are none:

Kanizsa's triangle

You see a complete white triangle, don't you? It is equally hard not to see 2d figures as 3d objects. This is why ambiguities in 2d figures cause the familiar "flip flop" effect (here between a cube seen from a higher elevation and a cube seen from below, or between a white vase in front of a black background and two profiles in front of a white background).

Necker's cube and figure/ground ambiguity

In short, the visual world is constructed in conformity with the cookie cutter paradigm (CCP) — the notion that the parts of a material object are defined by the parts of the space it occupies, and that the parts of space are defined by delimiting surfaces (boundaries). In other words, the multiplicity of things existing at any one time rests on surfaces that carve up space much as cookie cutters carve up rolled-out pastry.

Because the visual world is constructed in accordance with the CCP, it is only natural that we should try to construct our model of the physical world along lines laid down by the CCP — and that we should be perplexed beyond measure by Nature's refusal to follow suit. In the next article we will examine some of the paradigm's implications and see how they lead us down the garden path.