A study of the notion of Type in Architecture raises a host of difficulties, that start with the meaning of the word itself. To give a precise definition of Type is as difficult as coming up with a definition of Form, a term often used as synonym of Type. Type and Form are tautological notions, self-evident trues that elude definition. Type, like its most generic equivalent, Form, is a fundamental category on which human knowledge is based. We find the notions of Form or Type underlying all intellectual work, from the distant past up to the present day. In fact, it would be difficult to find an intellectual creation, either a scientific theory or a work of art, in which a notion of Form has not played a central role.

The ubiquity of the terms Form and Type makes it difficult to delimit their study to a particular historical moment or even to a particular discipline. Moreover, it can be contended that any attempt to confine the study of Form or Type to a historical moment necessarily distorts the essential meaning of the concept. By the same token, a study of Type restricted to architecture could be, in principle, equally misleading. The essence of the meaning of Type transcends historical periods and specialized fields. Therefore, to grasp the true meaning of Type it is necessary to take the broadest possible view, considering the term Type as a `conceptual model' or paradigm that permeates every intellectual creation.

The notion of Type in Architecture

With the regard to the notion of Type in Architecture, it is necessary to distinguish among the following cases:

1. The explicit use of the term type in the texts of architectural theorists. This case is limited to a few instances at particular historical moments. Among them, the definition of Type given by Quatremère de Quincy in 1825 stands out. This is still the main point of reference in any discussion about Type in architecture. The concept of Type of Quatremère re-entered the architectural debate in the 1960's and 1970's, particularly because of the article of Giulio Carlo Argan, `On the Typology of Architecture', first published in 1962. About the same time, the concept of Type became the fundamental epistemological category in the theoretical work of Carlo Aymonino, Aldo Rossi, Giorgio Grassi, and others. Following the work of Italian architects and urbanists, a considerable number of articles and books dealing with the issue of Type in architecture has been published. To give a comprehensive list of those works is beyond the scope of this introduction.

2. Other synonyms which convey the meaning of Type. Ever since Vitruvius, architectural theorists have given expression to the idea of a first architectural model -a type or archetype- from which architecture derives, without making explicit mention to those terms. For example, Laugier did not use the term type, but turned to the simile of the cabane rustique to convey the idea of a first architectural model. Other authors have used terms which come close to the idea of Type as a first principle. Viollet-le-Duc, for example, used style in the sense of a formative principle that pervades every true work of architecture; a meaning that comes close to the previous definition of Type given by Quatremère. Similarly, in the field of the psychology of form a number of terms have been coined that convey the notion of a `mental image' that matches the formative principle that lies in the object; that is, the type. The notion of Gestalt is a point in case. Art theorists who have based their work on the findings of the psychology of form have come up with their own terms. For example, Rudolf Arnheim's notion of `structural skeleton' or Ernst Gombrich's `conceptual schema'. More recently, some architectural theorists have preferred to use other terms to avoid the numerous connotations with which the words type or form have been loaded. Bruce Allsopp, for example, uses the word format to refer to a patterned structure which includes not only form but also function, design system and style.

3. The illustrated architectural treatises which gave expression to the notion of type and typology without explicit mention of these words. After the publication of Serlio's books in the Renaissance, the illustrated architectural treatise has given expression to the notion of type and typology in architecture, by means of images rather than words. Later books, such as those by Palladio, Scamozzi, Ledoux and Durand, among many others, have continued the tradition of giving expression to architectural typology by graphical means. In all of these treatises, the word type either was not mentioned at all or it was replaced by others that conveyed a similar meaning. For example, Durand, in his Précis des leçons, used the French genre instead of type.

4. The evidence provided by architectural works. The most eloquent manifestation of Type in architecture is provided by the architectural works themselves. Any coherent group of architectural works, like the Greek temples, the Palladian villas, the Prairie houses of Wright, as well as examples of vernacular architecture, are all tangible manifestations of the notion of Type.

Structure of the work

This work is structured in two parts. The first part, confined to the first chapter, explores the different meanings of Form and its synonyms Idea, Type and Structure. The second part, consisting of the following ten chapters, explores in chronological order the notion of Type in architecture, covering each of the four manifestations of Type referred to above.

FIRST PART: Meanings of Form: Type, Form, Idea and Structure

The first chapter addresses the concept of Form in the broadest possible sense, by exploring the different meanings of Form in the realms of philosophy, science and art. One of the purposes of this inquiry is to establish a distinction between Type and other terms often used as synonyms, like Form, Idea and Structure. In this regard, this chapter aims to go beyond a simple etymology of those terms. It shows that each word -idea, type and structure- stands for a `conceptual paradigm' or `model of thought', that pervades the intellectual productions of a given period. Thus, it will be contended that the concept of Type stands for the epistemological meaning of the more comprehensive notion of Form; and that Type belongs to a territory where the differences between science and art tend to blur.

SECOND PART: The concept of Type in Architecture

The following ten chapters focus on the architectural meaning of the notion of Type. The overall structure of this second part is mostly chronological. It begins with the doctrine of imitation of Plato and ends with the most recent concepts developed around the application of computers to design. This sequential ordering does not imply that there is a historical continuity in the development of the different conceptions of Form and Type. Sometimes, a historical thread is stressed, for example the one that begins with the concern with form perception in the Renaissance and ends with the attainment of an identity of conception and perception in modern architecture. But, in general we have avoided following a strictly historical development because this would distort the essential meaning of the notion of Type. As can be seen in the course of the different chapters, Form, or Type, is the recurrent issue behind much architectural thought expressed by theorists at different times.

A brief description of the content of every chapter follows below:

Chapter two, is a study of the doctrine of imitation contained in Plato's theory of Ideas of Forms. The understanding of Plato's theory of imitation, particularly with regard to the different objects of imitation he considered, is a prerequisite for the appreciation of Quatremère's theory of Type.

Chapter three, concerns itself with the theory of the origins of architectural form propounded by Vitruvius. Vitruvius' theory of the origins of architecture has remained the essential reference for later theoreticians who have addressed the issue of the first architectural model.

Chapter four, is a discussion of different aspects of the Renaissance conception of Idea, including the emergence of form perception in the architectural theory of Leon Battista Alberti; the relation between conception and representation with regard to the concept of disegno; the architectural treatise and the systematization of architectural knowledge; and the natures of the Renaissance conception of architectural form. The aim of this chapter is to demonstrate the specificity of the Renaissance Idea in contrast to later notions of Type.

Chapter five, makes a case for the increasing awareness with form perception, in the epistemological sense, that took place in the course of the seventeenth and eighteenth centuries. Topics in this chapter are: the theory of Claude Perrault, the work of British architects in the early eighteenth century and the ideas and projects of Etienne-Louis Boullée.

Chapter six, concentrates on the emergence of the concept of Type in architectural theory. The theories of Marc-Antoine Laugier and Quatremère de Quincy are the subject-matter of the chapter.

Chapter seven contains a critical review of the theoretical work of Jean-Nicolas-Louis Durand.

Chapter eight, discusses the intersection of meanings of Type and Style which took place in the first half of the nineteenth century, as manifested in the theories of Heinrich Hübsch, Gottfried Semper and Eugène Viollet-le-Duc.

Chapter nine, focuses on the meaning of Type as a mental image, in particularly with regard to those artistic theories born under the influence of the psychology of form perception. The different ideas and terms developed by writers like Adolf Hildebrand, Heinrich Wölfflin, Paul Frankl, Emil Kaufmann, Rudolf Arnheim and Ernst Gombrich, are reviewed and discussed. The purpose of the chapter is to make a case for the identity of conception and perception as a distinctive feature of modern architecture. The ideas and buildings of Le Corbusier are a specific example.

In chapter ten, the alleged break of modern architecture with the idea of Type is questioned, while it is proposed that the transformation of architectural form from the Renaissance to the Modern Movement is characterized by the abandonment of the Palladian model and its subsequent replacement by the notion of formal language.

Finally,chapter eleven, furnishes a view of Type as mind structure that derives from those fields that have attempted to study the mind scientifically, by modelling on the computer the creative processes, including design. In this chapter, the idea of a systematic design process supported by computer is contrasted with previous ideas formulated in architectural theory.