A Sense-Datum: Mind-Dependent Objects in Perception - Essay Sample

Introduction

A sense-datum is a mind-dependent object that a human being is directly aware of in perception, and it portrays the exact properties it appears to have (Huemer 2011). For example, when one stands in front of a mirror, he or she sees a reflection that does not correspond to anything in the external world to his or her mind, since the image appears to be located in a space beyond where the mirror is placed; for instance, a wall. Consequently, the image is a mental object that can be considered as a sense-datum. Also, when one sees a tomato, he or she forms a mental image of a red and round fruit. Although one can doubt the presence of a tomato, none can dispute the existence of its characteristics; consequently, they make up sense data for the object. The sense-data theory received both support and opposition from various philosophers. Bertrand Russell was one of the greatest endorsers and developers of the theory in the early 20th century. Russell's philosophy tied him to the idea that sensory experiences are instances of awareness of sense-data, which is noticeably different from everyday material things (Speaks 2007). However, this idiocy was rejected by philosophers such as Sir Alfred Jules Ayer, Wilfrid Sellers, and John Langshaw Austin. The critics questioned the existence of sense-data, and the properties they appear to have. While the opponents of the theory make logical points to back their argument, the presence of sense-data can be validated through the analysis of experiences.

Russell's Concept of Sense-Data

The concept of data of the senses was developed in the late 19th century, especially in the work of William James (Coats 2005). Russell was one of the philosophers who refined the sense-data theory in the first half of the 20th century. For Russell, experiment and observation can only give data of sense, for instance, sounds and patches of color (Speaks 2007: 1). As a result, physical objects can be verified solely through their correlation with sense data. Russell viewed sense-data not as a mental state, but as an actual part of the subject-matter of physics (Speaks 2007: 2). Also, Russell saw the possibility of sense-data existing without ever being perceived; stimuli can exist without being sense data (Speaks 2007: 2). By physical, Russell meant anything that can be studied by physics; to him, sense data are physical, but not as matter or things. To support this claim, Russell argued that sense data lack the properties of elements of matter; for example, molecules have no color (Speaks 2007: 2). Also, sense-data cannot be a thing because one object, a table, for instance, has more than one sense-datum, depending on the many perceptions of it. Moreover, an item cannot be identified by any single characteristic of its appearance; for example, one cannot identify an object like a table because of its round shape alone since it a shared property with many other items.

Sense data are logically not dependent on awareness, whereby the subject is conscious of them; therefore, they can exist outside the consciousness, without any acquaintance to a subject (Coates 2005). A sensibilia only becomes sense data after going into relation to awareness in the mind of a person (Coates 2005). For instance, the red color becomes a sense-datum after being associated with the redness of an object, for example, a tomato.

Arguments Against Sense-Data

Different philosophers have challenged the existence of sense-data and questioned whether it has the properties it claims to have. The very characteristics of the theory have raised mixed discussions in history, with the opponents rejecting the notion that sense-data exists in a form different from the existence of ordinary objects (Coates 2005). The objections are grouped into several categories discussed below.

The Appeal to Physicalism

One of the primary reasons against sense-data is the idea of physicalism in the philosophy of the mind. Physicalists believe that the world and the objects in it are entirely physical, and mental states are inexistent or are reducible to mere physical states, for instance, in the brain (Huemer 2011). This contrasts the sense-data theory, which holds that material objects are different from (as embraced in dualism), but dependent on mental states. The philosophy thinkers against sense-data argue that it does not fit in the physicalism picture. For example, a sense-datum is expected to portray the characteristics that perceptually appear to us; however, the objects with such properties are the external ones we are perceiving (Huemer 2011). In cases of hallucinations and illusions, there are no physical objects with the features that perceptually appear in mind. In other words, the brain states lack the characteristics that perceptually appear in mind; therefore, if a sense-datum exists, it must be a non-physical thing.

Epistemological Objections

There are at least three epistemological arguments against the sense-data. First, the theory leaves human thinkers unprotected from the external world skepticism (Huemer 2011; Coates, 2005). If we are only always aware of the non-physical phenomenon and our sense-data, then the reason for believing that physical objects exist is unclear (Huemer 2011). Berkeley (1710: section 20), as quoted by Huemer (2011) pointed out that it is logically possible for someone to share the same sense data that he has; however, there are no physical objects around that person, that he took to be in his surroundings. Therefore, Berkeley did not see any point in believing that such physical objects exist.

The second argument holds that a sense-data theorist cannot justify our concept of physical objects, or our ability to conceive their properties. The reason for this judgment is according to the sense-data theory; physical objects cannot be observed in the same way in the same way as sense data (Huemer 2011). For instance, while the sense-data may be red and round, the actual tomato may be invisible; therefore, it makes no sense that the color and shape can resemble that which cannot be seen - similar argument holds for other properties as well. According to the sense-data theory, we are not directly aware of physical things and their properties, which cannot resemble the objects we are aware of; consequently, we could lack the apprehension of the nature of physical objects (Berkeley, 1710; sections 8-10).

The third objection is derived from the work of Sellars, who challenged the idea of foundational empirical knowledge, which is knowledge gained from immediate experiences (Huemer 2011). Russell (1912) argued that one has a sense-datum, hence infallibly and immediately aware of it - referred to as being acquainted with or sensing. By virtue of acquaintance, one can know he or she has a sense-datum. Consequently, the inferences one makes about the external world are to explain the series of the sense-data in possession. The third objection proposes a dilemma as to whether the immediate awareness of the sense-data submitted by Russell is propositional in form or non-propositional (Huemer 2011). Sellars proposed that if consciousness is propositional, then it necessitates the application of concepts (Huemer 2011). For example, if one is aware that the sense-data are red and round, they must first have the idea of roundness and redness. This brings a challenge because the perceptual precede and not depend on concepts (Huemer 2011). Conversely, in case awareness is non-propositional, it cannot give the knowledge proposed by Russell because knowledge is propositional; a proposition cannot be supported by a non-propositional state (Huemer 2011).

The Existence of Sense Data

Critics argue that if the properties that perceptually appear to us belong to sense data, then a visual sense-datum has a size and a shape. Consequently, it is must be logical to assume that they are located in space; nevertheless, sense-data theorists do not provide a plausible answer to this assumption. For instance, since sense data are in one's head, they can be viewed as mental states; however, this can be problematic because brain states lack the properties that appear perceptually in physical objects (Huemer 2011). Also, if one proposes that sense data are located in the same place as the objects causing them, the association of sense data with hallucinations will be challenged. Similarly, if one proposes that sense-datum is located where it appears to be, the approach might be problematic for non-existent locations, such as fictional locales in dreams (Huemer 2011).

The Argument From Indeterminacy

The properties presented in perceptual experience should be similar to those in sense data. For example, if one has the experience of seeing a red object, then the sense-datum is red; else, one lacks the red sense datum. The problem with this view is that the properties an object appears to have by observation are sometimes indeterminate. For instance, an object might appear to belong to a given range of colors, while it seems to belong to no specific shade. Similarly, under the waterfall illusion, objects appear to be moving within a given time interval without a change in the relative position in the visual field (Huemer 2011). Consequently, the sense-data theory might appear to demand a sense-datum with inconsistent properties.

Arguments for the Sense-Data Theory

Although valid and plausible claims accompany the objections posed by critics against sense-data, the theory can be sufficiently defended by analyzing experiences to counter the doubts directly. Contemporary thinkers of physicalism reject the sense-data argument, stating that either mental states do not occur, or can be reduced to physical states (Huemer 2011). However, O'Shaughnessy avoided the differences between the two states by raising an argument that supports the similarities between both sense-data and brain states, making the two appear identical (Huemer 2011). Therefore, sense data experiences and brain states share the same properties, despite being experimentally incompatible and different. For instance, color, location, and shape might be in one's brain state but are sense data for a given physical object.

The first epistemological objection to sense data holds that the theory leaves human beings vulnerable to external world skepticism (Huemer 2011). The existence of material things cannot be deduced from the facts about the sense data one has (Huemer 2011). To counter the skeptical challenge, sense-data theorists proposed that human beliefs about the physical world are influenced by explanation to the best account (Huemer 2011). For example, although we have never seen a molecule, we are aware off its existence because the theory pertaining it best explains its characteristics and behavior as a tiny body. The second objection holds that the sense-data theory cannot account for our ability to perceive physical objects. However, this claim is limited since we see material objects because of the sense-data representing them. The third epistemological reason for the rejection of the sense-data theory is based on Sellars' questioning of traditional empirical knowledge. However, the Sellars dilemma and argument were not directed towards the sense-data theory (Huemer 2011). Also, Sellars confused the idea of conceptual awareness with propositional. For instance, one might have an immediate awareness of a specific shade of color for which he or she has no preexisting concept as a sense of datum; this is non-conceptual but prepositional.

Another widely accepted objection to the data-sense theory is that the appearance of the properties of a physical object is sometimes indeterminate, meaning that they lack definite characteristics. However, in logical consideration, this is impossible; for instance, an obj...