Understand that we have no grasp at all of the fourth mode, which is the essence of the person himself, without the substance. For the five senses, and our imaginations, will suggest to us only manifestations of the essence, but nothing of the essence itself.15An example of the essence, the fourth mode, is the intangible, ineffable self that we each manifest through our bodies. In simple terms, this can be thought of as your soul, your self, the irreplaceable "you" that shines out and can be perceived by others through your actions and self-expression.
This core essence of our being is beyond words and can never be grasped or directly contemplated. This core essence exists within all things and can be thought of as the divine life-force powering each creation. These essences cannot be perceived directly with our senses. Instead, we can only perceive their physical impact and manifestation within the measurable material world.
Thus, for example, the sense of sight merely presents us with traces of a visible essence which are visible because of the light. Similarly, the sense of hearing is merely the ability to perceive sounds from air (sound) waves striking an entity. The air that is pushed away by its force strikes our eardrums, and thus we hear that there is some entity in our vicinity. The sense of smell is only air (odorant molecules) that emerges from an entity, which strikes our olfactory receptors, and so we can smell.
Likewise, taste is nothing more than the result of the contact of some entity with our taste buds. Consequently, all of these four senses present us only with manifestations of the activities that are caused by some entity, but nothing of the entity itself.