Many syntactic dependencies turn out to be semantic in nature, and these dependencies seem to arise from a single resource. This resource is conjec- tured to be adjacency. The conjecture of semantics arising from order goes back about a century in mathematics, to Schönfinkel, and almost half a cen- tury in philosophy, linguistics and cognitive science, to Geach, Ades and Steedman. The natural meeting point of the two historically independently motivated theorizing about adjacency, the semantic and the syntactic one about combinators, is the main story of the book.

In this regard, the book was bound to be a historical account from the beginning. However, it came to provide, in some detail, ways of theory and model construction for linguistics and cognitive science in which there is no degree of freedom from adjacency. This pertinacious course seems to set up the crucial link between forms and meanings with as little auxiliary as- sumptions as its progenitors can think of. I believe it sets up creative links in theorizing about the computational, linguistic, cognitive and philosophical aspects of grammar. I exemplify these connections one by one.

When we look at combinators as functions they are too powerful, equiv- alent to the power of a Turing machine. As such they cannot do linguistic work because natural language constituency narrows down the expressible semantic dependencies manifested by functions. The linguistic theorizing be- gins when we syntacticize the combinators and establish some criteria about which combinator must be in the grammar and which one can materialize in the lexicon. An explanatory force can be reached if the process reveals predic- tions about possible constituents, possible grammars and possible lexicons, without the need for variables and within a limited computational power. Structure-dependence of natural language strings can be predicted too, rather than assumed.

Every intermediate constituent will be immediately interpretable, and non- constituents will be uninterpretable by this process. In other words, being a constituent, being derivable and being immediately interpretable are three manifestations of the same property: natural grammars are combinatory type- dependent. These are the narrow claims of Combinatory Categorial Grammar.

1

Words would be very unnecessary, as one songwriter put it in the early 90’s.

2

The apparent similarities of these theories must be put in context. As Pol- lard points out frequently, most theories subscribe to some form of syntac- tocentrism because they conceive the relation between forms and meanings as indirect. It must be mediated by syntax. The theory covered in the book is syntactocentric in Pollard’s sense. The syntactocentrism that will be argued against here is the one that sees semantics as an appendix to syntax. The theory presented here is neither the first nor the only remaining one on this stance.

We need only look thirtysomething years before the rise of that kind syn- tactocentrism to find an alternative foundation for bringing semantics into syntax. Two historically independent programs, radical lexicalization and codeterminacy of syntax and semantics, culminate in a theory where adja- cency is the only fundamental assumption. Two aspects will figure promi- nently: dependency and constituency. Both will get their interpretation from a single source, the semantics of order.

For the reader the book is organized in such a way that the technical ma- terial that gets in the way of linguistics have been moved to appendices. This leaves some aspects of combinators, grammars and computing to the appen- dices (mostly definitions and basic techniques). Linguistic theorizing about the combinators is in the main text. There is no reference to the appendices from the main matter, or from appendices to the chapters in the main body. The back matter is organized such that the latter ones might refer to earlier ones. Reading all the appendices in the given order might help readers who are unfamiliar with some of the terminology.

Now to pay some debts old and new academic and personal. This book started as my I-see-what-they-mean project, although I am not sure about the end result. It was an attempt at a collective understanding of Moses Schön- finkel, Mark Steedman, Anna Szabolcsi, Pauline Jacobson, Noam Chom- sky, Richard Montague, Haskell Curry, Emmon Bach and John Robert Ross, among others. I hope I’ve done them justice.

At a more personal level, my first contact with Mark and his theory was in the years 1992–1994, and since then it has become a major part of my aca- demic life. I have asked so many questions to Mark (not to mention numerous requests for judgments on difficult English examples) that I am slightly embarrassed I am getting away with an acknowledgment. Before then I was for- tunate to be taught by great teachers, whom I’m honored to list in somewhat chronological order: Türkân Barkın, Metin Ünver, ̇Ibrahim Nis ̧ancı, late Esen Özkarahan, Nicholas Findler and Leonard ‘Aryeh’ Faltz. Some friends and family taught me more on academic affairs than I was able to acknowledge so far. There is a bit of them in the book but I cannot exactly point where. Thank you Canus ̧, née Cihan Bozs ̧ahin, Nezih Aytaçlar, Zafer Aracagök, Ug ̆ur Atak, Ragıp Gürkan, Justin Coven, Uttam Sengupta, Halit Og ̆uztüzün, Samet Bag ̆çe, Sevil Kıvan, Aynur Demirdirek, Mark Ellison and Stuart Al- lardyce.

I am solely responsible for not heeding good advice of so many good people.