Page 230 - Encyclopedia of Philosophy of Language

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(a) Node A c-commands node B if every (3) branching node dominating A dominates B.
(b) A node is bound if it is coindexed with a c- commanding
node.
(c) A node isfree if it is not bound.
These definitions are formulated in terms of stan- dard phrase structure trees. It is assumed that readers are familiar with this type of representation and with terms like 'node' and 'dominate.' The intuitive notion behind the formal notion of c-command is something like being higher in the tree or being superordinate. To test whether A c-commands B, trace up the tree from A until a branching node is encountered and then seek a path down the tree to B. Other definitions of c-command have been proposed in the literature, replacing the criterion of 'branching' with a different one.
The principles of BTcan now be presented although a few key technical terms will be left undefined for the moment:
(a) Principle A: An anaphor must be bound by (4) an antecedent in its governing category.
(b) Principle B: A pronominal must be free in its governing category.
(c) Principle C: An R-expression must be free.
The term anaphor here is used to cover reflexive pronouns and reciprocal expressions (e.g., eachother; replacing themselves by each other in (2) does not alter the pattern of grammaticality). The term 'pronominal' covers nonreflexive pronouns. 'R-expressions' are noun phrases that are not pronouns (i.e., names and descriptions). The phrase 'in its governing category' in the principles corresponds to the word 'nearby' in the informal statement of the observations above. Extensive discussion has gone into giving the phrase a precise definition, and a number of candidates have been proposed, each of which has many other impli- cations for the theory of grammar. For present purposes, we will simplify considerably and say that the governing category of an element is usually the minimal NP or S properly containing it. (There are cases in which this simplification is inadequate, includ- ing those with anaphors in the subject position of nonfinite clauses, which sometimes has no governing category, and positions internal to certain NPs, where the governing category is not the minimaldominating NP. Some such cases will be discussed below.)
Returning to the simple cases, Principle A of BT says that reflexives and reciprocals must have c-com- manding antecedents in the same clause (as in (2a)) or minimal NP (as in Mary,'s picture of herself-). Principle B says that nonreflexive pronouns cannot have c-com- manding antecedents in the same clause (2c) or mini- mal NP (*Maryj's picture of her,). Principle C entails that neither kind of pronoun may c-command its ante- cedent (2e). It also says that even those R-expressions
that may take antecedents can never be c-commanded by their antecedents; this is illustrated by (5).
(a) When John, arrived, the idiot, sat in the (5) wrong chair.
(b) *John, regretted that the idiot, sat in the wrong chair.
The brevity and relative simplicity of BTis decep- tive: it represents the culmination of many years of research into these topics, and it embodies a number of important insights that emerged during those years. Hence, a fewcomments are in order.
First, BT does not actually say which elements may be the antecedents of which others. Rather, it gives the conditions under which pronouns may or must be bound. While the data on which BTis based are intuitions of antecedence, those intuitions do not necessarily coincide with binding relations. In particu- lar, the reference of a pronoun may be understood to be the same as that of another NP that does not c-command it, as in (6); but it is built into the defin- ition of binding that only c-commanding NPs may bind a pronoun.
(a) John.'s mother loves him,. (6) (b) The fact that we teased the children, upset
them,.
Notice, however, that nothing in BTprohibits co- indexing in these cases. Indeed. BT says nothing about which NPs pronominals may be coindexed with; nei- ther (6) nor (7) is explicitly covered by the principles.
John, thinks everyone loves him,. (7)
BT only says that there are certain NPs which pro- nominals must not be coindexed with. This is because, quite generally, nonreflexive pronouns need not have antecedents in the same sentence. For that matter, they need not have linguistic antecedents at all—that is, they can refer to salient entities that are not men- tioned in the discourse. Hence BT, unlike most earlier work, does not pair nonreflexive pronouns with ante- cedents. But it permits coindexing in just those environments where speakers find coreferential interpretations possible.
Second, BT has no asymmetry based on linear pre- cedence. That is, it permits pronouns to be bound by elements that follow them. Initially, this may seem counterintuitive, for it is natural to think of anaphoric elements as deriving their interpretations from some- thing previously mentioned. But there are cases of 'backwards anaphora' (or 'cataphora,' as it is some- times called), such as (8).
If he, is lucky, John, will win. (8)
While there have been a number of proposals that do include linear precedence as one factor governing anaphoric binding, BT follows Reinhart in claiming that the relevant structural factors are hierarchical.
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