"As Rosch (1977) has established, we categorize things in terms of prototypes. A prototypical chair, for us, has a well-defined back, seat, four legs, and (optionally) two armrests. But there are nonprototypical chairs as well: beanbag chairs, hanging chairs, swivel chairs, contour chairs, barber chairs, etc. We understand the nonprototypical chairs as being chairs, not just on their own terms, but by virtue of their relation to a prototypical chair." (#60 2135)
"We understand beanbag chairs, barber chairs, and contour chairs as being chairs, not because they share some fixed set of defining properties with the prototype, but rather because they bear a sufficient family resemblance to the prototype. A beanbag chair may resemble a prototypical chair in a different way than a barber chair does. There need be no fixed core of properties of prototypical chairs that are shared by both beanbag and barber chairs. Yet they are both chairs because each, in its different way, is sufficiently close to the prototype." (#60 2138)

people categorize objects, not in set-theoretical terms, but in terms of prototypes and family resemblances

"We are using the word "prototypical" in the sense Rosch uses it in her theory of human categorization (1977). Her experiments indicate that people categorize objects, not in set-theoretical terms, but in terms of prototypes and family resemblances. For example, small flying singing birds, like sparrows, robins, etc., are prototypical birds. Chickens, ostriches, and penguins are birds but are not central members of the category—they are nonprototypical birds. But they are birds nonetheless, because they bear sufficient family resemblances to the prototype; that is, they share enough of the relevant properties of the prototype to be classified by people as birds." (#60 1274)

prototypical direct manipulations → ...

"Piaget has hypothesized that infants first learn about causation by realizing that they can directly manipulate objects around them—pull off their blankets, throw their bottles, drop toys. There is, in fact, a stage in which infants seem to "practice" these manipulations, e.g., they repeatedly drop their spoons. Such direct manipulations, even on the part of infants, involve certain shared features that characterize the notion of direct causation that is so integral a part of our constant everyday functioning in our environment—as when we flip light switches, button our shirts, open doors, etc. Though each of these actions is different, the overwhelming proportion of them share features of what we may call a "prototypical" or "paradigmatic" case of direct causation." (#60 1256)
"These shared features include: The agent has as a goal some change of state in the patient. The change of state is physical. The agent has a "plan" for carrying out this goal. The plan requires the agent's use of a motor program. The agent is in control of that motor program. The agent is primarily responsible for carrying out the plan. The agent is the energy source (i.e., the agent is directing his energies toward the patient), and the patient is the energy goal (i.e., the change in the patient is due to an external source of energy). The agent touches the patient either with his body or an instrument (i.e., there is a spatiotemporal overlap between what the agent does and the change in the patient). The agent successfully carries out the plan. The change in the patient is perceptible. The agent monitors the change in the patient through sensory perception. There is a single specific agent and a single specific patient." (#60 1261)
"(In physical causation the agent and patient are events, a physical law takes the place of plan, goal, and motor activity, and all of the peculiarly human aspects are factored out.)" (#60 1285)

causation is best understood as an experiential gestalt → ...

"We would like to suggest instead that causation is best understood as an experiential gestalt. A proper understanding of causation requires that it be viewed as a cluster of other components. But the cluster forms a gestalt—a whole that we human beings find more basic than the parts." (#60 1253)

the complex of properties occurring together is more basic to our experience than their separate occurrence

"They recur together over and over in action after action as we go through our daily lives. We experience them as a gestalt; that is, the complex of properties occurring together is more basic to our experience than their separate occurrence. Through their constant recurrence in our everyday functioning, the category of causation emerges with this complex of properties characterizing prototypical causations." (#60 1280)