Mrs. Eddy says: "Mortal mind sees what it believes as certainly as it believes what it sees. It feels, hears, and sees its own thoughts" (Science and Health, p. 86). According to the present view the material world is the source of information upon which the human mind depends for its development, and the physical senses are the avenues through which this information is received. No retrospection is deemed possible without material sensation as a basis, either directly or indirectly. These trusted servants thus seem to be the pillars of existence to the human mind.
Sensation is considered as the impression made in the human consciousness when nerves are stimulated. In many cases the evidence thus reported is reversed by a consideration of relations which prove it to be untenable, but the majority of the impressions received are yet believed, and these govern the thought of human beings. The organs of sensation, called the five senses, have been the subject of a vast amount of study and discussion, and the volumes which have been written on them would fill many a shelf. Their construction and operation have been worked out in great detail, but after all this painstaking work the scholars who have given their lives to it confess that the goal of their research has eluded them. No matter which of the senses is studied, these reluctantly uttered words describe the last step in its operation: "In some unknown manner, the impression is transmitted into consciousness." After a lifetime study of the brain, an eminent professor of biology was asked what conclusions he had come to regarding the human brain, and he answered, "None."
The mechanism of sensation is very attractive to the human mind, because it there recognizes many familiar laws of mechanics, optics, and acoustics in operation. It has learned to rely upon these asserted laws, and is much gratified to know that they have an important place in its very existence. This circumstance seems to give unity to the whole fabric of physical being. The study of these delicate mechanisms has, how ever, never succeeded in showing that there is any connecting link between what is experienced in human consciousness and the instrumentality which seems intended to bring this experience about. This is the more remarkable because of the elaborate detail and precision of operation found in the sense organs.
