Phenomenalism

Phenomenalism is a philosophical theory or belief concerning perception, knowledge, and physical reality. For the phenomenalist, there is no other reality than that of phenomena and everything that exists exists as a phenomenon. Contrary to idealism, with which it is often associated, phenomenalism admits that there are objects external to our mind, but it considers that these objects are reduced to their sensible appearances. It is about a radical form of empiricism and anti-realism for which nothing corresponds to the supposed notion of thing in itself or of noumenon.

The central thesis of phenomenalism is that there is no difference between the world and our experience of it. The objects that constitute the world are objects of perception which, as such, can only exist within our experience. There are therefore no entities endowed with an autonomous existence, nor a metaphysical world subsisting “outside” our experience.

Phenomenalism also maintains that objects are logical constructions from the many perceptions we have of them.

Origin and developments

This thesis has its origin in the empiricist philosophy of George Berkeley and David Hume. But it was from the 19th century within the positivist school that it developed, in particular with the physicists Ernst Mach and Pierre Duhem initially, and with the Cercle de Vienne in a second time.

For Mach, the world is a complex of sensations. In this moving fabric of colors, sounds, pressures and various disparate sensations, more or less stable regions appear which are imprinted in memory and find their expression in language. We call bodies those relatively stable complexes of light and tactile sensations associated with spatial and temporal sensations.

In its more contemporary version, notably in that presented by Alfred Jules Ayer, phenomenalism considers that the world is exclusively made up of sense-data (the equivalent of qualia in current vocabulary). To justify itself, this theory puts forward the “argument of illusion”: if I can be the victim of an illusion (or of a hallucination) without knowing it, it is because nothing allows me to distinguish between a true experience and an illusion when faced with it. Therefore, the nature of truthful experience cannot be radically different from that of illusion. In both cases, I immediately become aware of a set of sense-data, that is to say of small sensations whose reality lies entirely in their appearance.

Phenomenalism goes beyond the conclusion of the illusion argument, however. It also offers a radical reinterpretation of the notion of reality and more particularly of the meaning of empirical statements such as “it’s raining outside” or “the snow is white”. Such statements seem to relate to a physical world that goes beyond our experience of it. But this is forgetting the phenomenal and conceptual character of the physical objects to which we are referring. For the proponent of phenomenalism, any reference to a physical object or to an event must be understood as relating to a logical construction of sense-data. A table, for example, is nothing more than a bundle of sense-data of which only some are currently perceived when I see the table, the other sensory aspects of the table being likely to be perceived if I change my point of view on it. All these sensations are integrated into the concept of the table that I have forged on the basis of my experiences.

Controversies

Phenomenalism comes up against several difficulties. One of them concerns the explanation of the fact that we evaluate some of our experiences as being “true” or more generally “correct”, and others as being “illusory” or more generally “incorrect”. The very presentation of the illusion argument supposes the possibility of identifying some experience as “illusory”, that is to say as not corresponding to reality. However, it seems that the phenomenalist conception of experience does not make it possible to distinguish between reality and illusion or mere appearance.

One possible answer to this difficulty is to consider not an isolated experience at a given time, but all the experiences over a certain period of time. A true experience can then be defined as an experience which fits coherently into a long series of experiences. Consequently, an illusory experience is an anomaly which is poorly integrated into the series of experiences which precede and follow it. In a different context, Edmund Husserl speaks of the unity of a “concordant” experience, that is to say a coherent set of experiences. An illusion is then considered as an incoherence or a “discordance” within this whole which forms a system.

Include texts translated and adapted from Wikipedia