2.1. Concept 1. Theory
As currently used, the term “land-use theory” refers to two distinct types of theories: theories approaching land uses and land-use planning through an analytical perspective, and theories dealing with the process of land-use planning itself. We do not have today a “pure”, analytical land-use theory. A prerequisite for the discussion of the nature of a possible theory of this kind is the epistemological delimitation of the general nature of theory itself, because, once this is defined, it offers the guidelines for the constitution of any particular theory.
We may distinguish two broad categories of epistemological positions, to which realist and anti-realist theories correspond. According to realist theories, it is possible to know the essence of the world. Scientific theories are considered to be true, at least approximately, in the sense that they correspond to an external reality; they are theories-reflection and their truth is truth-correspondence. Contrary to realist theories, anti-realist theories exclude truth-correspondence. They exhibit two major tendencies. The first is mild anti-realism, for which, while reality cannot be directly re-presented, it nevertheless exerts pressures on the content of theories and thus the latter cannot be arbitrary. The other tendency is radical conventionalism, an extreme relativism that holds that science is purely and solely a construction, totally disconnected from reality; thus, observations do not pose any constraints on the researcher and in theory-building he/she is completely free [
6] (pp. 43, 109–118, 126). We recognise in this last tendency the position of postmodernism.
I do not doubt the value-laden nature of theory. We need not go back as far as Marx and his social constraints on knowledge; Michel Foucault’s concept of
épistémè is convincing enough on the matter: each historical period is marked by this unconscious epistemological order that defines the very preconditions of knowledge [
7] (pp. 11–14, 384, 385). However, we should understand
épistémè as guiding knowledge only in the final instance. Theory as a whole, in spite of the value elements that it involves, cannot be simply identified with values; it is a language game with its own specificity. Science is different from other mental activities. Every science is oriented towards an in-depth analytical knowledge of its object, and implies the marginalisation of the value factor as far as this is possible.
The constitution of any theoretical field is founded on an initial epistemological decision. This decision implies the use of the “law of relevance” (
loi de la pertinence). The rationale on which this law is founded is that no science is in a position to exhaust the description of any empirical object—and this is even more obvious when the object in question is a city or region. Each science has to choose only
one of the possible perspectives through which an empirical object can be approached, and this is the criterion of “scientificity”: among the numerous possible features of an object, only those necessary and sufficient to exhaust its targeted analytical description should be included. The requirements for a scientific description are, in order of importance, that it be free of contradiction (coherent), exhaustive, and as simple as possible; from these requirements follows the procedure governing scientific description [
8] (p. 23), [
9] (pp. 10, 11, 18), [
10] (Description, Opération, Pertinence, Procédure). A similar epistemological position is adopted by Davoudi and Pendlebury, with the difference that they refer generally to disciplines of any sort. They conceive of a discipline on the epistemological level as having a particular (not necessarily exclusive) object of enquiry, theories and concepts to organise knowledge, and specific research methods. I would call this aspect of a discipline its structural dimension. To this dimension, the authors add a functional one. They broaden the prerequisites for the constitution of a discipline beyond epistemology to what they consider its social dimension, referring to a common language and circle, individual identities and careers, on the one hand, and to its academic, professional and scientific (journals and conferences) institutionalisation, on the other [
2] (pp. 616, 617).
I would argue that it is not conceivable to practice land-use planning without a land-use theory: not an economic, or an environmental, or any other kind of theory, but a purely “functional” theory. That is, we need to develop an analytical land-use theory, but, to substantiate this proposal, we first need to define the object of land-use planning, theoretically as well as in direct link to practice. This is what will be attempted with the following concept.
2.3. Concept 3. Classification of Land-Use Theories
Since land uses are the starting point for the existence of land-use planning, when seeking to define an analytical land-use theory we should logically turn to urban (and regional) uses to establish the appropriate perspective on the empirical world and define the epistemological object of enquiry of such a theory. This is, in fact, the typical perspective used by planners during the analysis stage of a plan, though it is used in an ad hoc and empirical manner, devoid of a coherent theory. We could call this emerging field “spatiology”; it would include an “urbanology” and a “regionology”.
We accept as a normal fact, and rightly, that, for example, behind economic planning, spatial or not, lies (analytical) economic theory and behind environmental planning, the science of ecology. There is no theoretical reason why, in the field of land-use planning, no analytical land-use theory has been formulated; indeed, this lack is rather surprising. Not only is there an object of scientific study, but also (as we saw above) an epistemological framework into which to insert this object. Of course, no practice follows directly from the exclusive use of a corresponding theory, because, as we saw, every theory is constituted as an abstraction from the empirical world, while practice takes place in the middle of it and must thus be much wider in its scope than theory (on this matter, see below the axis–framework concept).
In order to situate spatiology within the constellation of
land-use theories, it is useful to recall Andreas Faludi’s distinction between procedural theories and substantive theories. Procedural theories are theories
of planning, which according to Faludi concern the form of the planning process and the operations of the planner, or otherwise the organisational forms of planning procedures, and should be the object of planning theory. Substantive theories are theories
in planning, which refer to the content of planning and the fields that are of interest to the planner. He also makes a parallel distinction between normative planning theory (comparable to political theory
) referring to the rational process of planners, and empirical planning theory (comparable to political science
), the knowledge of the organisation and procedures of planning. Planning theory is, for Faludi, normative and focuses on the way the planning process should proceed rationally [
13] (pp. 1–4), [
14] (pp. 3–8), [
15] (Preface). To bring these two classifications together, we should consider the procedural theories
of planning as identical to
normative planning theory, and the substantive theories
in planning and empirical planning theory as two different domains of scientific,
analytical knowledge: the first domain provides the foundation for planning methodology and the second the context of planning theory and practice. Thus, Faludi makes a clear distinction between normative, in the sense of rational, technical process, and analytical. In spite of the centrality of process in planning for Faludi, he emphasises his preoccupation with spatial analysis, which he marginalises in the name of process, without, however, denying the importance of analytical knowledge for planning.
An argument against the procedural–substantive distinction was put forward by Allmendinger, who, based on a post-positivist rationale, takes the position that theory is a discourse, dependent on socio-historical conditions and to a greater or lesser degree normative, whence he concludes that substance and procedure cannot be distinguished. He argues that the normative dimension involves values, aims at defining the way things
ought to be, and offers the means to achieve the desired situation. He concludes that, if the procedural–substantive distinction were preserved, theories of planning would be part of normative theories. Allmendinger thus implies a close connection between procedural and normative, in the sense of value-laden, but adds that both the procedural and the substantive approaches include both normative and analytical elements. Allmendinger also adopts a distinction between two forms of rationality: the formal rationality of means, such as the use of formal procedures to achieve defined ends, and substantive rationality, including values and morals about these ends, which relates values to the substantive dimension; and criticises the overemphasis of planning on the first form [
1] (pp. 2, 12–18, 32, 33, 38, 39, 41, 42, 210). This last distinction is of crucial importance. Faludi refers to normativity in its
technical aspect, while Allmendinger mainly thinks of values, that is, he approaches normativity through its
axiological (value-laden) aspect. I shall come back to this point later.
Allmendinger’s view on planning normativity follows from his idea on the value-laden nature of theory. I agree that theory is socio-historically bounded and value-laden (I already referred to its flexible relationship with épistémè). We adopt two different epistemological viewpoints: Allmendinger tends to radical conventionalism, while I opt for mild anti-realism. However, Allmendinger’s position is contradictory, because on the one hand he emphasises the “normative” nature of theory, while on the other he accepts the existence of analytical—manifestly in the sense of value-free—elements.
In this context, it is important to distinguish between analytical theories and applied, technical fields. Unlike science, an applied field such as land-use planning is value-guided and frequently politically so. The two spheres, (scientific) theory and (applied) practice, are of an almost radically different nature, because in the first case, values are only a point of departure, though an inescapable one, to obtain a knowledge as far as possible analytical, while in the second values are the regulatory factor for the operations taking place: science is analytical and describes and explains what is, planning practice, on the other hand, is value-laden and proposes what ought to be.
Of course, no absolute distinction can be made, because there is a certain overlapping between the two spheres. There are also intermediary positions. Thus, between the analytical and the axiological, I would place, in addition to technical normativity which is strongly related to the analytical, the axiological extension of analytical theories, as well as critical theories. However, the general orientations of the analytical and the axiological are strongly divergent. Without this distinction, we cannot understand the distance between science and planning, nor the integration of planning within a sphere different from the scientific one, namely that of empirical practice. To put it in the simplest possible way, this distinction in land-use planning amounts to the distance between the descriptive statement “this is a compact city” and the axiological, prescriptive statement “we must build compact cities”.
Such prescriptions cannot have any straightforward theoretical justification. We may have recourse to a great number of analytically founded rationales, among which one based on the rational agent of economics, another borrowed from the idea of carrying capacity in ecology, and so on, or such choices may be purely subjective. However, the final choice of one or some among the above is analytically undecidable, and two proposals for the same area within different planning contexts (Right-wing or Left-wing mayor?) may opt for the selection of different goals. In the same vein, Heather Campbell [
16] conceives of the integration of the (analytical) “is” within the (synthetical) normative/axiological and uncertain “ought”; the result, as she points out, is a planning which cannot go beyond the “better”, but which allows for action.
The substantive dimension of land-use planning includes both the analytical-scientific and the axiological dimensions. The latter is, as we saw, pointed out by Allmendinger, but is not explicitly included by Faludi in his typology. Thus, Faludi’s distinction between scientific and normative could be considered deficient, but not for the reasons given by Allmendinger, that is, the rejection of the procedural–substantive distinction.
Allmendinger advances a typology of land-use planning theories and formulates a framework, of a post-positivist nature as he sees it, identifying the theoretical influences on planning theories, which he also links to their socio-historical situations. He defines five categories of theory involved in land-use planning [
17] (pp. 89–95), [
1] (pp. 41–46):
a) Framing theories. These are comparable to a paradigm or an epistemology and cover planning “doctrine”. Allmendinger considers the modern and postmodern perspectives as the most abstract forms of framing.
b) Exogenous theories. These are “meso-level” theories, that is, not general theories of society, but focused on a particular aspect of it; they are not specifically concerned with planning, but are relevant to it. However, his reference to the superior-level cognitive psychology and to the very narrow example of the relationship between car usage and the decline of town centres blurs the theoretical status of this level.
c) Social theories. These aim at a general understanding of society.
d) Social scientific philosophical understanding. This indicates broad approaches, such as positivism, Marxism, idealism, or phenomenology, seen by Allmendinger as underlying different social theories.
e) Indigenous planning theories. These are planning-specific, derive from the above forms of theory and are politically and generally socially situated.
In other words, Allmendinger proposes two groups of theories, one sociological and philosophical, (b), (c) and (d)—oddly, he does not include environmental–ecological concerns—and another that is planning-oriented, (a) and (e); (a) includes the foundational perspectives of land-use planning and regulates indigenous (or rather endogenous) theory.
Allmendinger’s attempt at typology is dynamic, context-sensitive and thus interesting, although it focuses on land-use planning theory itself and the theories integrated within it. From this point of view, it is poorer than Faludi’s approach, which also takes into account analytical perspectives on land-use planning (see
Table 1). What is missing from both typologies is an analytical theory of land uses
as such, what I have called spatiology.
A typology of land-use theories should concern not only planning theories. We need to formulate a complete initial typology, before any kind of elaboration such as the one proposed by Allmendinger. The theoretical foundation for a typology covering all the theories relating to land uses and land-use planning should develop in two steps.
First, by distinguishing between, on the one hand, analytical theories concerning land uses (scientific land-use theories) and land-use planning, and on the other technical theories of land-use planning. Among analytical theories, we should differentiate between the theory of land uses specifically, spatiology the analytical theory par excellence of land uses (which presents a certain analogy to Michael Neuman’s “functional urban theory” that follows Kevin Lynch), and two other types of analytical theories relating to a) land uses, such as certain theories derived from human geography, and b) land-use planning, such as Faludi’s empirical planning theory, the approaches dealing with the analysis of land-use planning proposals and with planning performance measurements, the justificatory approaches to planning, or the Marxist approach to land-use planning as social practice.
In the case of land-use planning theories, the differentiation is between normative theories in the axiological sense and in the technical sense. We encounter two types of the former: a) theories offering “idea” land-use organisations (Neuman’s “normative urban theory”, that also follows Lynch) and b) theories referring to the ideal aims of land-use planning, such as ethics and social justice (Neuman’s “normative city planning theory”). The normative theories in the technical sense coincide with planning methodology (Neuman’s “functional urban planning theory”, that still follows Lynch—[
18] (pp. 135–137). The latter is the focus of land-use planning (
Table 1).
There are also other typologies of this kind, of less interest for land-use theories. For example, John Friedmann distinguishes between theories
in planning, specific to its different specialisations (such as land-use, transport, or environmental planning), theories
of planning, referring to the common elements of the theories above, and theories
about planning, which he equates with critical planning, such as the Marxist approach [
19] (pp. 7, 8). As we can see, the first two types concern not only land uses, but all types of spatial planning, while only the third, corresponding to the analytical theories relating to land-use planning, is specific to land uses. Criticizing Friedmann, Ernest R. Alexander [
20] rejects as ideology the possibility of general theories
of planning, believing that theories depend on contingent contexts. However, he is then inconsistent in accepting theories
in planning, because they also concern different social contexts, and in considering that theories
about planning should also be contingent, a view disproved by the Marxist case.
We understand now the position of spatiology within the constellation of land-use theories. It is, in my opinion, the most important of the scientific land-use theories and the one of most interest as a background for applied urban planning, that is, for normative land-use planning theory, which is, in turn, the major approach for operational urban planning. The Marxist approach, for example, among the scientific land-use theories, is of high interest for the understanding of the function of planning within the capitalist system, but offers no clues for operational urban planning. Below, I shall refer to certain approaches related to spatiology and briefly discuss some of the major issues of a theory of spatiology.
2.4. Concept 4. Analytical Land-Use Theory
Spatiology, while theoretically obvious, has been almost invisible in land-use approaches. However, it is by no means a new invention, but comes from a tradition in human geography dating from the period 1930–1960 and is excellently represented in an article by Allen K. Philbrick [
21]. In planning, it was advanced and elaborated statistically in Greece, a country with a poor tradition in the field; however, it was developed by an internationally known institution, the Athens Center of Ekistics led by Constantinos A. Doxiadis [
22] and, still in the Greek context, was given a structuralist form by Alexandros P. Lagopoulos [
23]. We find a recent reminder of the existence of such a theory in Neuman’s above-mentioned functional urban theory, concerning “city structure and function”.
A striking attempt to define an analytical land-use theory is illustrated by J. Brian McLoughlin’s systemic approach. It is to the credit of McLoughlin that he conceived the need for, and to a certain extent used, a scientific land-use theory. This orientation is first manifest in the four general systemic elements of space that he orders into two pairs: the pair of components, namely activities (land uses) and the spaces in which they are located (their physical counterpart), and the pair of their connections, namely human communications (between activities) and their channels (their physical counterpart). The four elements of his system are thus founded on a theoretical conception of activities, on the basis of which he arrives at a theory of land uses. His orientation toward such a theory is apparent in his interest in a typology of land uses, since he agrees with the view that this typology “should deal with
activities only—a ‘pure line’ classification” [
24]. He gives a few ad hoc examples of typology taken from professional practice and proposes the Standard Industrial Classification as a guide for land-use typology—[
24] (pp. 34, 77–79, 129–133, see also [
25] (p. 323). However, it is only possible to achieve such a task, and in general to establish clearly the contents of the elements of the system, by previously systematically posing the theoretical basis of a land-use theory, without subjugating it to the empirical modes of planning.
I would like to outline here some of the major issues of a theory of spatiology. Its theoretical constitution implies the definition of elementary urban and regional uses. In this paper, I generally use the term “land use”, because this is the traditional term we use in planning. Actually, this term is a shortcut, due to the usual mapping procedure during both analysis and the formulation of a planning proposal. While this term is literal in the case of regional space, in urban space, though practical reasons lead to a focus on rather general categories of land uses, that is, a two-dimensional representation of space, this is a simplified representation, because urban space is three-dimensional and thus urban uses develop on many levels. The implication is that a theory of uses cannot have as its starting point the condensed projection of uses in plan, but must conceive of uses as analytical (sociological) constructs and in a more detailed manner, before their projection onto geographical space. On the basis of elementary uses, it is possible to identify more complex groups of uses, as well as the relationships between the different hierarchical levels of uses. McLoughlin’s typology is an instance of the search for a classification of such uses and also of the elementary units themselves. They are not obvious. For example, spatial “functions” also exist in architecture (such as living rooms, hospital rooms, restaurant kitchens), but in architecture these are units in the internal structuring of a larger unit, which itself is an elementary urban unit. Urban and regional units are different from architectural units. On the other hand, the perspective which is relevant for urban and regional units cannot, by definition, simply coincide with the economic perspective, whatever their relationship, and so units such as those provided by the Standard Industrial Classification and comparable classifications are at the very least only a rough approximation.
Theoretical work is needed in order to define the specificity of the nature of urban and regional uses as products of specific social spatial practices. The elementary urban unit cannot be defined on the basis of its spatial location, a current conception which obstinately marks the urban planning legislation of all countries. On the contrary, it must be defined (socio)logically by its nature as a product of the above practices. In order to understand the futility of trying to define the units as a function of their location, we have only to think of the non-sense of trying to define social classes on the basis of their location in space, instead of starting from a solid sociological theory.
In practice, these units are defined in an empirical and ad hoc manner, which regularly results, both in more theoretical approaches and in legislation, in a simple linear enumeration. This is far from a systematic classification of uses (McLoughlin’s preoccupation), which is the sine qua non condition for a concise theoretical approach to the issue and a useful guide to practice. The basic typological matrix must not be linear or nearly linear, that is, consist of only one or two levels, but must be hierarchical and multi-layered. This implies the continuous integration of the groupings of units of each lower level of the matrix into the immediately higher level, finally arriving at the most general categories of uses or, in the opposite direction, starting from the most general category of uses and by continuous decomposition creating each time smaller homogeneous groups down to the unitary uses. Operations of this kind imply explicit and relevant criteria of grouping, and the partial criteria used in each case must both be logically interrelated and compose a logical whole [
26]. Thus, for example, retail trade may be divided into General Retail Trade and Retail Trade in Services, and the former may be divided into Daily, Occasional and Infrequent according to the criterion of frequency of visits by customers, and so on.
A series of concepts is articulated around the concept of the unitary urban use. The theoretical matrix outlined above classifies the urban uses themselves, not their location, another crucial concept. Location is the social projection of parts of the matrix in geographical space, and thus it is a secondary phenomenon in respect to the primary one of classification. Thus, each urban use occupies a usually fixed location, depending on its nature, as recorded in the matrix. When manifested in space, it belongs to a double physical vehicle, built space (which presents a series of attributes, such as height and volume), and its lot; it has size, and the latter is measured by the relevant theoretical units (surface, number of people of different kinds); it is characterised by a dynamic function, its relationships (both theoretical and in actual space) to other uses; it creates a specific catch area.
Elementary units are grouped into spatial clusters of similar and/or different units, and there is a continuous development of these clusters, from the block to urban areas of a nodal character, such as the city centre, or a specific nature, such as residential areas or industrial zones. On this level, new concepts emerge, such as homogeneous and polarised areas. Different quantitative indices follow from the relationships between units of urban measurement, such as density, useful for analysis but also for planning. By organising the above field of more specific concepts, it is possible to construct a spatiology.
This concept closes the discussion of analytical land-use theory, which corresponds to the two first levels constituting a theory, the epistemological and the theoretical levels. The following second part corresponds to the third level, methodology, which concerns the procedure of applied planning.