Sense and Its Function

a) sense A sense is a capacity for directly perceiving and knowing a certain kind of material object.. It is an organic faculty, that is, it is knowing-power which operates by means of a special bodily part or member, called a sensory, or sense-organ, or simply an organ. A sense perceives and knows individual material objects which affect it, stimulate it, impress it.

A sense is an animal faculty. Plants do not give any sign of possessing senses. All animals have one or more senses, and hence animals are called senSENSE-KNOWLEDGE 43 tient beings. The so-called “higher” animals have external and internal senses, that is, senses with outer bodily organs, and senses which have their sole organ in the brain. Man has normally all the external and internal senses of which we have any knowledge.

The most commonly accepted division of the senses designates them as external and internal. The external senses have their organs or sensories in the outer body, the body surface, the periphery, and they function by means of a complex nervous and muscular connection of their organs with the cerebrospinal axis and the brain. The internal senses have their organ in the brain itself. The external senses are usually enumerated as five, viz., sight, hearing, smell, taste, and touch. The internal senses are four, viz., the central sense (called sometimes the common sense), imagination, sense-memory, and the estimative sense or instinct.

Some authorities distinguish two senses in what we call the sense of touch. These speak of a resistance-sense and a temperature-sense. Others assert the existence of a special muscular-sense, by which the subject is aware of the feelings of skin, joints, and muscles in bodily movement. For our part, we include all these senses in the single sense of touch, or, as the man in the street calls it, feeling.

Nor do we admit any special sense of pain or sense of pleasure. Pain is due to over-stimulation of the sense of touch, and sense-pleasure may be loosely described as the result of perfect functioning of the senses under desirable conditions.

The Object of Sense

That which is capable of impressing sense and stirring it to react in the operation of sense-cognition is the object of sense. In a word, the object of sense is anything that can be known by sense, anything that can be sensed. This is the general meaning of the term object of sense. The object of sense is called sense-object, sensible object, or sensile object. Sometimes the adjectives sensible and sensile are used as nouns, and an individual object of sense is called simply a sensible or a sensile, and sense-objects collectively are called sensibles or sensiles.

A sensible object that can be known directly in itself by any sense, is called the object per se of that sense (Latin per se, “through itself,” “of itself”).

Thus the color and the size of an apple are per se visible, that is, the color and size are per se the object of the sense of sight. The flavor of the apple is not per se visible, but it is per se the object of the sense of taste.

Besides sensiles per se, there are other senseobjects; these are sensible per accidens (Latin per accidens, “by way of accident,” “accidentally,” “dependently upon something else”). These objects either do not fall under the senses at all, or they do not fall under the particular sense to which they are ascribed as objects. They are directly {per se) known by the intellect, or by some other sense than that to which they are referred. They are so referred because they are known by experience to belong to, or to be associated with, the per se object of the sense in question. Thus a dairyman sees that milk has become very sour. The sourness of the milk is not per se the object of sight, but it is such an object per accidens because very sour milk has a peculiar appearance which is visible. Similarly, one sees that the street is wet after a shower. The wetness is not per se visible, but experience has taught us that this peculiar appearance is associated with wetness, and hence the wetness is visible per accidens. Again, the flavor of an apple is not per se visible, but it may be visible per accidens to one who is familiar with the qualities of the fruit. If such a person be told, “This apple is sweet,” he may answer, “I see it is.” What he really sees is the color of the apple, together with its shape and size; these qualities are per se visible.

And because the person knows by experience that apples of this color, shape, and size, are sweet apples, he is said to see the sweetness, not indeed in itself (per se), but as a thing known to be associated with what he does see; he sees the sweetness per accidens, or accidentally. He also sees that the apple is a bodily substance. Now, substance is not per se sensible at all; it is known by the intellect. Continual and varied experience teaches us early in life that any object marked by the qualities of size, shape, and color is a substantial thing, is a thing bodily; hence material or bodily substantiality is sensed per accidens.

Going back now to sensiles per se, we find these divided into two classes. Those that are sensed by one sense alone constitute the proper object of that sense. Those that are sensed by ‘More than one sense constitute the common object of the senses concerned.

Thus colored objects are sensed as colored by sight alone and by no other sense. A man born blind can have no notion of what color is in terms of other sensibles. Recently a young man who had been blind from birth submitted to an operation that gave him his sight. When he visited the school for the blind which he had attended for many years, his old friends clustered around him and begged him to tell them what color is like. He was utterly unable to do so. Color (not in the abstract, but in concrete existence, as a quality of bodily things, that is, color as extended, or colored surface) is the proper object of the sense of sight and is the object of no other sense.

The size of an object is sensed by sight (through the medium of color; for if it be not colored, it is not visible, and so its size is not visible). The size of an object is also sensed by touch (through the medium of resistance or temperature, for if it have not these, it is intangible, and therefore its size is intangible).

Size, then, is known by sight and by touch. I may know the size of an apple by looking at it, and also by holding it in my hands. A blind man may know the size of such an object as well as a man with normal vision may know it. Therefore, size is not an object proper to sight alone, or to touch alone; it is an object common to these two senses. Again rest and motion in bodily objects are knowable to sight and to touch, are objects common to the two senses.

The classification of sense-objects as sensiles per se and sensiles per accidens, and the sub-classification of sensiles per se as proper and common objects of sense, are distinctions of the first importance and must be accurately learned. It is a matter to which constant reference will be made in a subsequent stage of our study. It may be summed up for ready review in the following schema: ‘proper to one sense alone per common to two or more senses Sense-Objects - ^per accidens C) SENSATION Sensation is the conscious reaction of the subject to sense-impression. A sensile object, falling within range of a sense that can grasp it, impresses the sense by acting upon the sense-organ, and causes the subject to become aware of the impression, or rather, of the object. This awareness is sensation. As a result of sensation, the subject is in possession of the object; it has cognitional existence in him; he cognizes it or knows it. This knowing-act of sense is called perception.

Sensation and perception are really only two distinct aspects of the one operation, which we call sense-cognition. Inasmuch as this operation means an awareness in the subject, it is sensation; inasmuch as the same operation means the representation or represence of the object within the subject, it is perception. I experience sensation, and perceive the object.

The representation of the sense-object within the sentient subject—that, is, the cognitional re-presence of the object in the sentient knower—is called the percept. Sense-knowledge is made up of percepts.

Each percept is the knowledge of some phase of an object, and the sum-total of the percepts that the senses garner from an outer reality gives full senseknowledge of that reality. As you take your morning coffee, you perceive (that is, you have a percept of) it as colored, by sight; as hot, by touch; as having an aroma, by smell; as flavored, by taste. The sum of the percepts makes up your sense-grasp of this object, this cup of coffee.

The object, falling within range of sensecognition, under conditions suitable for the operation of the sense concerned, impresses the senseorgan. In other words, a sense accepts from its object an influence which results in the representation or re-presence of the object within the knowingSENSE-KNOWLEDGE 49 subject. This operation—the actual nature of which is studied in the sciences of physics and psychology —may be likened (but not with perfect accuracy) to the reflection of an object in a mirror. The mirror receives and reflects an image of what is placed before it, provided the object so placed is suitable, proportionate to the size of the mirror, and properly illuminated. So sense receives and reflects within the subject an image of what impresses the organ, provided the object is suitable for the grasp of such sense, is proportioned to the function of the organ, and is presented under due conditions for the action of the organ. When all these provisions are verified, the image of the object is impressed upon the organ, becomes intra-organic, and so is the immediate object of sense-cognition.

The impression which a sense takes of its object is called a species, which means here, an image or representation. Inasmuch as the species is impressed upon the sense-organ and upon the sense, it is called an impressed species. To distinguish this impressed species from the intellectual species (of which we shall speak later), it is called the impressed senseimage or, in the commonly used Latin term, species impressa sensibilis. Reacting to the impression of the species, the subject cognizes or knows the object from which the species is received (through the wholly objective instrumentality or mediation of the intra-organic object, as we have already learned).

In seeing a tree, for example, the sense of sight receives the species or sense-image from the object under due conditions of light and distance. But the sense of sight does not see the species as such; the species is impressed upon the eye, becomes intraorganic, and is so the means by which the sense of sight sees the objective tree, the trans-subjective object. Vision, like all the external senses, perceives only such objects as are actually present and actually affecting the sense-organ. (Recall that the object of external senses is trans-subjective in matter, form, and presence.) The operation of seeing (like the operation of all external senses) is terminated, reaches its completion and goal, by actually attaining the object there present. Hence the knowingoperation of the external senses begins with the external (trans-subjective) object, which is impressed in species on the subject, and the subject reacts to the impression and (through the objective mediation of the intra-organic object) cognizes the external object itself. With the internal senses the process is somewhat different. For these senses (such as imagination) act when their outer object is no longer present, and for their action, they must produce an image or species within themselves, wherein an object, once present but now absent, is sensed. In a word they must express their species, and this expression terminates their knowing-act. An external sense terminates its operation, completes it and rounds it out, by cognizing an object then and there present and acting upon the sense-organ. The imagination terminates the operation by cognizing an object expressed in sensible species within itself. The intellect or mind terminates its operation by cognizing an object expressed in abstract species within itself. The point we wish to make is this: while the internal senses and the intellect have an expressed species as well as an impressed species, the external senses have an impressed species only. They do not express a species, for they cognize their object itself, there and then present trans-subjectively.

Summary Of The Article

In this article we have defined sense, and have distinguished the senses as external and internal.

We have defined the object of sense, and have classified this object as per se and per accidens; the per se sensiles we have distinguished as proper and common. We have defined sensation and perception; we have described the percept. We have learned that sense-cognition involves the impression of an image or species. We have seen that while the external senses require for their functioning a species impressa sensibilis (impressed sense image), they do not require, and do not produce, a species expressa sensibilis (expressed species) as the terminus of their Zoperation, since they cognize the trans-subjective object there and then present to their action.