We may perhaps begin our discussion with an examination of the experimental character of reality- When we speak of the object of (metaphysical) experience, we refer to it as reality (or ultimately real) or as "being", "what is", "what truly exists". When we say that something is or has existence, we generally mean that it is an object for the knowing consciousness and that it has its place in the system of object which is cognised by an observer. Thus we have (a) an observer and (b) an object of metaphysical experience and "the questions involving the relationship between the two have haunted the philosophers and the scientists alike from the dawn of reason," says Lincoln Barnett.[1]
The fundamental questions about the nature of reality remain the same from one age to another: the ultimate radically divergent answers[2] to the problem also remain the same in principle, but the point of view from which the problem is attacked varies with the age and also with the aim of the investigator. Surprisingly, however, there exists a fair amount of similarity not only between the answers given by different philosophers but also those given by scientists.
Broadly speaking we can divide all their views into two doctrines:
- Idealism[3] is the doctrine that all reality is mental. It asserts that there is no reality outside consciousness and all experiences are only the modifications of our own consciousness. Nothing exists but state of consciousness. Amongst the philosophers who support this doctrine are: Plato, Leibnitz, Berkeley, Hume, Kant, Hegel, etc. Amongst the scientists who support this view are; Sir A.S. Eddington, Sir James Jeans, Hermann Weyl, Ernst Mach, Raymond Poincare, etc..
- Realism is the doctrine that the fundamental character of the real is its independence of any relation to the experience of a subject. It asserts that what exists, exists equally whether it is experienced or not. Amongst the philosophers contributing to this doctrine are: Democritus and the Greek atomists, Aristotle, scholastic philosophers, Rene Descartes, Bertrand Russell, etc, while some of the scientists supporting this view are: Newton, Bohr, Albert Einstein, Hisenberg, Whittaker, Reichenbach, C.E.M. load, Sir Oliver Lodge, Prof. Henry Margenau, the Soviet (Materialist) Scientists, etc..
Some Philosophers have established "scepticism"[4] by asserting that nobody can know the true nature of reality, the reality according to them is an Unknowable.