CHAPTER XXI
We have found that sense impressions cause events of consciousness which produce judgments by recalling concepts of sensation, such concepts being reinforced and developed by the addition of new judgments. Judgments of perception still employ the same sense impressions in the construction of new concepts of form, while concepts of form are recalled when a judgment of form is made. A new concept of form is constituted by the increment of a new judgment of form. Therefore concepts of sensation are concepts of kind, while concepts of perception are concepts of form. As a judgment of sensation must always precede a judgment of perception, the same sense impression which gives rise to a judgment of sensation will, in the maturer mind of the infant, also give rise to a judgment of perception; therefore we are compelled to reconsider the sense impressions from which perceptions arise. Having already found how judgments of perception are considered and how such judgments are verified, we have now to exhibit in what manner there comes into existence a multitude of judgments of perception which are never verified, and yet are entertained in the mind as if they were veridical.
Fallacies of perceptions are errors of judgment respecting forms. Such judgments may occur through unverified judgments of sensation, and the fallacy is repeated in a higher state of mind. Judgments, when they are first made, are of slow growth, but when once made, by repetition they become habitual and do not arise in the corticle consciousness.
The human mind cannot perceive form without first sensing kind. On the other hand it seems almost impossible to sense a kind without at the same time perceiving a form, though we may pay attention to the kind or to the form at will. In our discussion of fallacies of sensation, we have tried to pay attention to the kind, but we have found that kinds were usually expressed as forms. The experimental observer, Miss Smith, not only spoke of colors as dissolving in succession, but at the same time the colors themselves were explained as forms. Most of the fallacies of sensation which we have cited in this discussion, most of those which appear in the general literature of the subject, and most of those which occur in experience are not only hallucinations of sensation, but they are also specters of perception, because the human mind rarely senses an object without at the same time perceiving the object. When I see the color of the rose, I see the rose as a form. When I see the color of the cloud, I see the cloud. When a word is pronounced in my hearing I hear the sound as a sound, perceive the person in the other room represented vicariously by the voice, and at the same time hear the word as a word and as a symbol of meaning. In general, the description of a sensation is best accomplished in terms of perception.
We must know things as kinds before we know them as forms, and we must first judge of things as kinds before we judge of them as forms. But when we already know things as kinds, we can re-cognize them as kinds by instantaneous judgments, and at once go on to cognize them as forms, or to make judgments about them as forms. In a former chapter, fallacies of sensation were often described in terms of perception, for they seem always to produce fallacies of perception, and in the state of mind under which they are produced it is the forms, not the kinds, which are of chief interest to the subject.
There are many misperceptions; so common are they as to be scarcely noticed. If a person will observe his own thoughts from moment to moment, he will be surprised at the number of fallacious perceptions which he makes, some of which are immediately corrected, others are corrected after lapse of time, and probably many others that are never corrected, because of their insignificance in the practical affairs of life. These errors of judgment are especially common in audition and vision, the two senses most highly vicarious. A sound may be obscure by reason of its faintness, or by reason of diverted attention. Sight may be obscure by reason of the twilight, or it may be obscure because attention is elsewhere directed. All such impressions may be veridical or may be fallacious. If I am intently listening for a sound I may interpret a sight for a sound; if I am intently looking for an object, I may interpret a sound for a sight. If I am intently listening for a particular sound and hear another, I may interpret it for the one I was expecting; if I am intently gazing in expectation of seeing one object, and another falls upon the field of vision, I may see in it the one for which I was intently gazing. These are all misperceptions.