The development of proximity analysis has resulted, since the early 1990s, in a variety of definitions of proximity that are always centred on two dimensions: put schematically, there is a spatial dimension and another non-spatial dimension. Nowadays, two approaches are used in this debate, approaches that differ depending on the place they grant to institutions. The first approach makes a distinction between three types of proximity, called geographical, organizational, and institutional, respectively. The second approach, which I have adopted and have been working on, is based on a distinction between two categories of proximity, called geographical proximity and organized proximity (sometimes also called cognitive proximity) respectively.

Geographical proximity is a matter of distance. In its simplest sense, it refers to the number of meters or kilometres that separate two entities (individuals, organizations, towns...). But it is relative:

• To the physical characteristics of the space in which activities take place. There is a difference between travelling on a flat road and climbing a mountain;
• To transport availability, the costs of transport and the income of individuals. High speed trains might allow people to travel faster from one point to another, but the cost of travelling on such trains can be prohibitive for part of the population, at least in the case of frequent travelling;

Thus, Geographical proximity is neutral in essence. It is more or less positive or negative, and potentially useful depending on human perceptions and actions. Finally, it proceeds from a judgment made by individuals or groups of individuals on the nature of the parameters that influence the geographical distance that separates them, to convert them into statements such as: “close to” or “far from”, “positive”, “negative”... this perception varies according to age, social background, gender, profession, environmental conditions.

Organized proximity also constitutes a potential that may be activated or utilized. It has to do with the different ways in which actors are close, not geographically but relationally. The qualifier “organized” refers to the arranged nature of human activities (and not to the fact that one may belong to one organization in particular); it goes beyond cognitive dimensions. Organized proximity rests on two main logics:

The logic of belonging refers to the fact that two or several actors belong to one same network, or even one same web of direct or intermediated relations. It can be measured through the degree of connectedness, connectedness which points to the existence of more or less Organized Proximity, and therefore more or less potential for interaction or common action.

The logic of similarity refers to the sharing of common mental representations. It manifests in individuals being at short cognitive distances from one another. They might be people who work on the same project, or who share cultural, religious or social values or speak a common language. Thus the logic of similarity facilitates the interactions between people who might not know one another but share the same frame of references.