Individuation and reference in memory: Proper names and definite descriptions

A theory is presented which assumes that individuals are represented by unique nodes in memory. To test the theory, simple facts were predicated of an individual person. Some facts referred to him by proper name, and other facts by his profession. In a before condition, subjects learned that the profession and name referred to the same individual before learning the facts, while in an after condition, they learned the identity after learning the facts. Subsequent to learning the facts and identities, subjects verified sentences based on what they had learned. Verification latencies indicated that in the before condition, one memory node was created to represent the individual, but two nodes were set up in the after condition. Assymmetries between proper names and professions indicate that the two types of referring expressions are treated differently in long-term memory.     

On Possibly Nonexistent Propositions

Alvin Plantinga gave a reductio of the conjunction of the following three theses: Existentialism (the view that, e.g., the proposition that Socrates exists can't exist unless Socrates does), Serious Actualism (the view that nothing can have a property at a world without existing at that world) and Contingency (the view that some objects, like Socrates, exist only contingently). I sketch a view of truth at a world which enables the Existentialist to resist Plantinga's argument without giving up either Serious Actualism or Contingency.     

Hobnobbing with the Nonexistent

Recent discussions of Geach sentences by Braun and Salmon are reprised. It is shown that the intractability of providing semantics for Geach sentences (using standard logical tools) is due to the assumption that quantifiers are ontologically committing. Representing the content of these statements is easy using neutral quantifiers. An important concern is consistent identity conditions for nonreferring terms. It may be thought that Meinongian-object approaches handle this better than Azzouni's no-objects-in-any-sense-at-all approach. This is shown to be false. How our truth-inducing practices determine truth values for empty-term statements is indicated—in particular, it is argued that our identification and distinguishing practices with “fictional entities” are parasitic on our practices with entities we take to be real. Examples from Austin—white dots on the horizon and specks—are among the test cases for the views developed here.     

Attentive tracking of objects versus substances

Recent research in vision science, infant cognition, and word learning suggests a special role for the processing of discrete objects. But what counts as an object? Answers to this question often depend on contrasting object-based processing with the processing of spatial areas or unbound visual features. In infant cognition and word learning, though, another salient contrast has been between rigid cohesive objects and nonsolid substances. Whereas objects may move from one location to another, a nonsolid substance must pour from one location to another. In the study reported here, we explored whether attentive tracking processes are sensitive to dynamic information of this type. Using a multiple-object tracking task, we found that subjects could easily track four items in a display of eight identical unpredictably moving entities that moved as discrete objects from one location to another, but could not track similar entities that noncohesively "poured" from one location to another-even when the items in both conditions followed the same trajectories at the same speeds. Other conditions revealed that this inability to track multiple "substances" stemmed not from violations of rigidity or cohesiveness per se, because subjects were able to track multiple noncohesive collections and multiple nonrigid deforming objects. Rather, the impairment was due to the dynamic extension and contraction during the substancelike motion, which rendered the location of the entity ambiguous. These results demonstrate a convergence between processes of midlevel adult vision and infant cognition, and in general help to clarify what can count as a persisting dynamic object of attention.