As all thoughts can be reduced to five types of internal function, all objects can be reduced to five bhutas or elements. The five great elements are called pancha-mahabhutas, and they are (1) Ether (akasa), (2) Air (vayu), (3) Fire (agni), (4) Water (apas) and (5) Earth (prithivi). The subtlety of these elements is in the ascending order of this arrangement, the succeeding one being grosser than the preceding. Also the preceding element is the cause of the succeeding, so that Ether may be regarded as containing all things in an unmanifested form. The elements constitute the whole physical cosmos. These are the real objects of the senses, and all the variety we see is made up of forms of these objects. 

Our sensations are the five objects. We sense through the indriyas or sense-organs. With the sense of the ear we come in contact with Ether and hear sound which is a reverberation produced by Ether. Touch is the property of Air, felt by us with the tactile sense. With the sense of the eyes we contact light which is the property of Fire. With the palate we taste things, which is the property of Water. With the nose we smell objects, and this is the property of Earth. 

There is the vast universe, and we know it with our senses. We live in a world of fivefold objects. The senses are incapable of knowing anything more than these element. The internal organ, as informed and influenced by the objects, deals with them in certain manners, and this is life. While our psychological reactions constitute our personal life, the adjustment we make with others is our social life. The yoga is primarily concerned with the personal life of man in relation to the universe, and not the social life, for, in the social environment, one's real personality is rarely revealed. Yoga is essentially a study of self by self, which initially looks like an individual affair, a process of Self-investigation (atma-vichara) and Self-realization (atma-sakshatkara). But this is not the whole truth. The Self envisaged here is a consciousness of gradual integration of reality, and it finally encompasses all experience and the whole universe in its being. 

While the psychology of yoga comprises the functions of the internal organ, and its physics is of the five great objects or mahabhutas, the philosophy of yoga transcends both these stages of study. The yoga metaphysics holds that the body is not all, and even the five elements are not all. We do not see what is inside the body and also what is within the universe of five elements. A different set of senses would be necessary for knowing these larger secrets. Yoga finally leads us to this point. When we go deep into the body we would confront its roots; so also in the case of the objects outside. When we set out on this adventure, we begin to converge slowly at a single centre, like the two sides of a triangle that taper at one point. The so-called wide base of the world on which we move does not disclose the truth of ourselves or of objects. At this point of convergence of ourselves and of things, we need not look at objects, and here no senses are necessary, for, in this experience, there are neither selves nor things. There is only one Reality, where the universal object and the universal subject become a unitary existence. Neither is that an experience of a subject nor an object, where is revealed a knowledge of the whole cosmos, at once, not through the senses, mind or intellect - for there are no objects - and there is only being that is consciousness. Yoga is, therefore, spiritual, superphysical or supermaterial, because materiality is shed in its achievement, and consciousness reigns supreme. This is the highest object of yoga, where the individual and the universe do not stand apart as two entities but come together in a fraternal embrace. The purpose of the yoga way of analysis is an overcoming of the limitations of both subjectivity and objectivity and a union of the deepest within us with the deepest in the cosmos.