Without doubt, a chair is a chair is a chair. But that is by no means everything. The fact is that there are any number of chairs which, if looked at more closely, different appreciably from one another in terms of shape, color, material and sitting position. Things are no different with stools. How many legs does it need? Is it destined only as a seat? What posture do we adopt what we choose it instead of a chair with a back? To be quite pragmatic, what is a shelf and how do the different models vary, whether they be fastened to the wall or free-standing units? Or to approach a completely different field: How has the office changed? How does office furniture today enable us to work and in what way did the items of furniture that are intended to support us become what they? The same applies to sofas. What different types of sofa are there and what do we associate with them? Do we only want to sit on a sofa, or lie on it, too? What desires and fantasies are conjured up by a couch, or by an ottoman? Are they our own or do unconscious associations from the days of yore continue to influence us? And what about armchairs and the things that we label with the sweet name of "multi-functional furniture"?

Masses of questions. If we square up to them then we sooner or later enter the terrain of product typologies. These promise to deliver what is often lacking, namely a clear view of things. There are different methods of creating systematic product categories using typologies. What they all share is the goal of summarizing a heterogeneous range of products into a group that is as homogeneous as possible. In this way, on the one hand significant differences can be highlighted between various products and, on the other, statements become possible within the groups on the which marketing strategy is likely to be successful.

Not that this is all. Because once you start defining the categories, product typologies and other forms of systematizing furniture of all kinds you discover not only a mass of product that obey the respective structural rules and can thus be pigeonholed but also any number of exceptions and border-line cases. Once we have developed a sharper eye it may even transpire that the one or other category is not so sound. Suddenly, different historical strata and layers emerge. Instead of finding evidence confirming the homogeneity of a specific group we discern new types that have changed the bigger picture. Leaps in development become apparent, as do ruptures, displacements and linkages, hitherto ignored contexts, relations and hierarchies.

Over the next few weeks we therefore want to try and present the most important product typologies while highlighting the ruptures and shifts in each lineage. Any number of "family similarities" will emerge, not to mention concurrences and difference in terms of formal aesthetics, structure, history, semantics and social reach.

If the experiment succeeds then the overviews we offer will inform you not only about all the different chairs, stools, tables, armchairs and sofas there are, but also tell a different history of design. Namely one that grasps the past not as a closed unit and the present not as its logical consequence, but which includes all the about-turns, the reprises, the revivals and ruptures that are of course part and parcel of designers' work.