Phenomenalism: Perceptions and the External World
Phenomenalism
Phenomenalism is a philosophical theory according to which knowledge is possible for something different from our own perceptions. Hume believed that this philosophical position is the only reasonable one, but that it contradicts natural or common sense beliefs.
Classical empiricism defended a thesis that inevitably leads to phenomenalism: When we perceive, what we really perceive is not something external to our mind but our own feelings. This point of view was reached in different ways, but essentially by noting that in the act of perception, the object perceived is not a real part of the experience of perception itself. It is not included as an object in perception itself but appears as something external to one’s mind, and the object is assumed or inferred. If I perceive the table where I write, the table itself is not a part of my perception. That perception is a mental thing; it is something that comes into my mind, and the table is a physical object, an object outside the mind itself. When I say I see a table, what I actually have in my mind is a collection of various visual sensations, but I do not have the table itself. All ordinary people and most philosophers believe that there are objects outside one’s own mind, which are the cause of our perceptions and, to a greater or lesser extent, have forms or aspects similar to those offered in their own experience.
The phenomenal point of view is so strange and contrary to common sense ideas that no empiricist accepted it fully and consciously. But his view is also ambiguous.
Hume believed that this belief is not due to the perception itself because it offers only feelings, not the objects themselves. Some impressions we refer to as external objects, but not others. Nor is it the result of the exercise of reason, since no one makes arguments to assert that what we perceive exists beyond the perception. Nor is it due to the strength or force or violence of certain impressions, because there are strong views that are merely subjective, such as some pains and pleasures. There is no rationale to explain the belief in the continued independent existence of bodies.
Hume pointed out two particular features of experience that are the basis of our belief in the existence of an external world: the consistency and coherence of our perceptions.
Impressions and Ideas
For Hume, all content of the mind is divided into impressions and ideas, simple and complex.
The terms used to refer to Hume’s psychic world are imprecise and, in many cases, encourage confusion. This is precisely what happens with this term. It seems reasonable to try to name everything that is in the mind: the same way that you may be interested in giving a generic name to all that we can find in the physical world, we wish to give a name to all that is in the psychic world. Hume called “feel” everything we can find in the mind, both the objects of our experiences and the experiences themselves. Hume’s use of this term is misleading since it serves both to describe a specific type of mental state and to refer to everything that is in our mind.
Hume presented various classifications of perceptions, but the most important are these two:
- Attending to the primacy and origin, they are divided into impressions and ideas
- They are classified based on whether or not they are simple and complex:
Simple perceptions: Perceptions (both impressions and ideas) that cannot be decomposed into more elementary perceptions. The perception of the black color of my table is a simple impression; the memory of that color is a simple idea. The perception of the table itself is a complex perception, more precisely a complex impression: it consists of simple impressions of color, form, and if I’m also touching it, texture, degree of heat, etc. If I close my eyes and replay in my mind the earlier perception, I have a complex idea.
Complex perceptions: Perceptions (both impressions and ideas) that admit a decomposition into simple perceptions.
Criticism of Causality
With this critique, Hume did not only oppose the traditional philosophical view but also one of the most deep-rooted beliefs in common sense. Hume held that our beliefs about causal links are extremely important because the scientific research of the physical world seems to be largely an investigation into the causes of observable phenomena. Also, because the cause-effect relationship is essential in our daily life, particularly in our expectations of future events, including those relating to how we act in the world to achieve our goals. We think we are very sure of what we do to heat water and prepare tea, what we do to move our bodies out of the room. Hume often repeated that our certainty about what will happen in the future is based on causal inferences. We feel that causality is given in the physical world and the psychic world and between the mental and physical world. In this sense, our basic attitude to the world is to assume that whatever happens, happens because there has been a change somewhere in the world because something else has brought it into being. This idea was expressed by philosophers with the definition of the principle of causality: everything else needs to exist.
The traditional arguments for causality were:
- There are, particularly from the standpoint of Aristotelian-Thomistic philosophy, four causes: material cause, formal cause, efficient cause, and final cause.
- A priori knowledge of causal powers is possible either through the knowledge of the concepts of things or through knowledge of the essences of things.
- We can use reason to establish the causal links between things.
- Causal links are objective links; they are relationships that really exist in things.
- Causal relationships are the result of forces or powers or capacities of things and establish the necessary links between cause and effect:
- If A causes B, then A has a certain power or virtue by which B appears as A.
- If A causes B, then necessarily in the world when we have A, we have B.
- The principle of causality, “everything that exists has a cause,” is an absolutely true principle with complete evidence.
- Our arguments are valid grounds that allow us to link objects offered to the senses and also to link these objects with realities beyond the empirical world.
Criticism of Abstract Ideas
Talking about abstract concepts is to accept the possibility of representing reality in a universal way and, by extension, the essence, the substance of reality. According to Hume, when I speak of the abstract concept of a triangle, I have in mind the image, the representation of a particular triangle, especially, to which I add the quality, the fiction, that it represents any triangle. Just as you conceive the idea of a dog, “I represent a particular dog, to which I add the quality, the fiction, to represent all dogs.” All ideas are, therefore, private. What we call concepts or abstract ideas are the result of an inductive generalization, from experience, which ends up giving the same name to all the objects among which I find any resemblance or similarity.
When I hear the name of an object, it conjures up the image of one of the objects that I associate with it. It is impossible to evoke each and every one of the objects, but I am also able to evoke other objects, instead of these, if the occasion requires it. What we call abstract ideas, universals, are specific ideas to which we have given some representative capacity based on the simple relationship or similarity between objects. Moreover, since ideas are copies of impressions, and impressions are always particular, there can be no ideas that are not specific.