The View of Modern Medical Science
According to modern science, light-vibrations from outside strike the retina and an inverted image is formed there. These vibrations are carried through optic tract and optic thalamus to the center of vision in the occipital lobe of the brain in the back part of the head. There, a positive image is formed. Then only, you see the object in front of you.
Perception According to Sankhya Philosophy
The real back-ground of perception is the Soul. Fleshy eyes are only external instruments for perception. Eye is not an organ of vision. The organ of vision is a center situated in the brain; so is the case with all senses. Mind is connected with the Senses, the Senses with the corresponding centers in brain and the centers, with the physical organs, to the external object. The mind presents the sensation to Intellect ; Intellect takes it to the Soul. Now, real perception takes place. Soul gives order to Intellect.
Then, Intellect, after proper decision and judgment and after taking into consideration the pros and cons of the subject on hand, gives orders back to the mind, for execution through the motor centers (organs of action). Intellect is the President and Judge who hears the statements of the Advocate, viz., the mind. Mind plays two parts, viz., (i) that of an Advocate and (ii) that of a Commander-in-Chief. After receiving decisive orders from Intellect, the mind acts the part of a Commander-in-Chief and executes the orders of Intellect through the five soldiers, the five Senses.
First of all, there is the instrument for instance, the fleshy eye. It takes the sense-impressions to the center. The mind is then connected with the center and the external instruments, namely, the physical eye, ear, etc. The mind carries the impressions still further and presents them to the Intellect, the determinative faculty, which reacts. Then flashes out the idea of egoism, which self-arrogates and identifies with lower self. Then the mixture of action and reaction is presented to the Soul who perceives an object in the mixture.
Knowledge comes through contact with objects. To know an object in the world, Senses, Ego and Soul are required. Senses will see the object. Mind will make it appear. Intellect, with the help of consciousness, will understand it. Mind, senses and the external instruments such as the physical eye, ear, etc., should all be joined together. Then only perception of an object is possible. The object comes in contact with the senses. The senses are linked to the mind. The mind is connected to the Soul. The Soul illumines. This is with reference to the physical plane.
Illustration of Perception
When you see a mango tree, it is external to you. There is externality. The mango tree is a mental percept. It is a mental concept also. There is no mango tree apart from the mind. You know the existence of the tree through the mind only. There is a mental image in the mind. The image in the mind plus the external something is the mango tree. Even if you close your eyes, you can get at the image through memory. The green color of the leaves is due to a certain rate of light vibrations (say, 10 millions of vibrations). These light vibrations strike at the retina and are taken to the vision center at the back of the brain. The mango-leaves have the power to split the white rays and absorb the green color only. So says science.
Your body also is as much external to you as that yonder mango tree. It is also a mental percept or mental concept. The mango tree is external to you with reference to your body only. The mango tree itself is a mere appearance that floats in the Absolute or the One Reality. As the mango tree is external to you from the standpoint of your body, and as the body itself is external to you, the idea of externality of the mango tree or this external universe is blown up now. The term internality also has a false existence only. There is internality only with reference to the externality. If the externality goes away, where is the internality? Both the terms internality and externality are mere illusions, creations of the mind. There is only the solid existence, the One Reality or Absolute behind the so-called internality and externality. That is the Real, Infinite. “I” is your own lower self.
Mind – Its Mysteries and Control by Sri Swami Sivananda