In our study of applying quantum to cognition we have identified five main aspects that play a fundamental role and that are specific to quantum stru… - Diederik Aerts

What is reality? What is space? And what is time? These are the three questions that we want to investigate taking into account the knowledge that we have gained by modern physics. Our intuitive prescientific conception of the world in relation with these three concepts is not very precise but could be summarised as follows. - Reality is everything that exists now in the present. The past has been real but is not anymore and the future is what shall become real but is not yet. - Space is the theatre where reality is in. It englobes all of reality. Till the birth of relativity theory all physical theories where compatible with this intuitive scheme. But when relativity theory entered the scene, these intuitive conceptions of space and time, and what is less recognised even till today, also the conception of reality, has got into problems.

Poincaré analyses how the reality of three dimensional Euclidean (or non-Euclidean) space, has been constructed from our daily experiences as a human being with the objects that are most important for us (rigid bodies), and closely around. This does not mean that this three dimensional space is an ‘invention’ of humanity. It exists, but the way we have ordered, and later on formalized it, by means of specific mathematical models, does make part of it. In other words, what we call the three dimensional reality of space partly exists in its own and partly exists by the structures that we have constructed, relying on our specific human experience with it.

The world around us can be construed as a huge "house" that we share with other humans, as well as with animals and plants. It is in this world that we exist, fulfilling our tasks, enjoying things, developing social relations, creating a family. In short, we live in this world. We thus have a deep human need to know and to trust it, to be emotionally involved in it. Many of us, however, experience an increasing feeling of alienation. Even though, with the expansion of society, virtually the entire surface of the planet has become a part of our house, often we do not feel "at home" in that house. With the rapid and spontaneous changes of the past decades, so many new wings and rooms have been constructed or rearranged that we have lost familiarity with our house. We often have the impression that what remains of the world is a collection of isolated fragments, without any structure and coherence. Our personal "everyday" world seems unable to harmonise itself with the global world of society, history and cosmos. It is our conviction that the time has come to make a conscious effort towards the construction of global world views, in order to overcome this situation of fragmentation. There are many reasons why we believe in the benefit of such an enterprise, and in the following pages we shall attempt to make some of them clear.