It seems that faith and reason are the two factors that have major influence on human behavior in individual, social, national and global relationships. Faith provides inspiration and direction. Reason is essentially mental reflection that can be used to separate facts from fancy and truth from belief. Reason uses prior knowledge to arrive at a decision. Faith alone, especially if unsupported by reason, can and does lead to fanaticism, which can create turmoil and conflict. Reason without faith can lose focus, change course and result in confusion. It seems that only a perfect harmony between faith and reason can lead to peace, stability and tranquility.
Many centuries before the time of Christ, India was witness to two parallel movements. They are called agama and nigama. The Vedas are the source of agama. This movement accepts faith, but relies heavily on experience and reason for a complete knowledge. Nigama derives strength from faith. A harmonized synthesis of the two movements is known as Sanatan Dharma. A common name used for it in the West is Hinduism. It allows people to follow their faith in isolation, but enjoins them to accept reason in social, national and global dealings. It never allowed use of force to propagate faith. It considers mind a divine gift to be used to develop understanding through logic. In this liberal ambience came Buddha, the founder of Buddhism, and Mahabir, the architect of Jainism. Note that neither Buddhists nor Jains nor Sanatanis ever fought a war with each other to establish supremacy of their faith.
Knowledge is a key concept in Sanatan Dharma. Each of the six orthodox systems of philosophy that evolved out of it, carry at the beginning a section on the Theory of Knowledge. The theory describes methods of acquiring knowledge. One of the points it emphasizes is this: a thought-structure that is used to propose a concept should not be used to prove it. What do we mean by "thought-structure"? The world we see consists of many physical forms. Sanatan Dharma explains that these diverse forms have evolved out of and are supported by a single entity or base. The visible forms have the same relationship with the base as a tree has with its roots. The part of the tree above the ground can be observed directly, but its roots are not as easily accessible to the eyes. Yet, people accept its existence on the basis of any one of the three possible thought-structures. The first is to accept as true the statement they read in a relevant book, or heard from a reliable expert that every tree has root that supports and sustains it. This is an example of faith or trust in a statement. Or, secondly, one could infer the existence of root on the basis of the observation that an unsupported structure topples in windy conditions and if wind does not topple a tree, it must have a root, which provides it with support against wind. Reason is the basis for this method. Finally, one can dig around the base and see the underground root. This method uses direct perception and involves work. Thus, we can use any of the three methods in support of a statement: Accept on faith, verify by inference or visualize through direct perception.
Sanatan Dharma is a harmonized synthesis between accepting facts on faith and verifying them using inference or perception. This synthesis can be found in the Vedas, the oldest extant literature. It was stated earlier that just like the root of a tree, all physical entities evolve out of a single base that is inaccessible to direct perception. Some of the Vedic verses are the poetic expressions of this hidden base or the Ultimate Reality visualized by the sages and seers in their highest state of consciousness. They visualized not only the Ultimate Reality, but also the gradual unfolding of the world order, which they called Rita and which later became known as Dharma. The Vedic verses portray Ultimate Reality and present a system of rituals to bring harmony between human action and the world order. The verses are the kernel of the Vedas. Their interpretation can be read in the section called Brahamanas, which are part of the Vedas. Intellectual reflections on the verses by people during their quiet retirement in forests are included in Aranyakas, also part of the Vedas. Finally, the Upanishads of the Vedas express in words the vision of the later sages during meditation. They confirm the truth of the Vedic verses and affirm the existence of One Reality manifesting in multiple forms. Notice in this the sequence of thought process that moves from one step to the next. If the vision of the Ultimate Reality is metaphysical, reason or the intellectual reflections of Aranyakas is very much part of analysis based on observable physical reality. The next step that takes one to direct perception of the Reality depends on a thought-structure that is a unique contribution of Indian epistemology or the theory of knowledge. In brief, the theory is about the method of relating a word or expression to what it actually represents.
Two philosophical systems, Sankhya and Yoga, were developed to explain the world and its experience to a person who does not want to or cannot be bothered with the intricacies of the above approach of the Vedic sages. They split the unique Ultimate Reality in two entities such that a common person with desire and dedication can understand them. One is called Purusha and the other is known as Prakriti. Purusha is Spirit that is available to us in the form of consciousness. Spirit is the source of consciousness. Prakriti is ever changing nature witnessed in the form of physical bodies or objects. It is the coming together of the two, Purusha and Prakriti, that is responsible for all the creative impulses and creation. These statements or those of the Vedas can be accepted as true on faith alone. But one needs an independent proof for these statements. To use the same source in support of a statement originating from it is not convincing. Another method, another thought-structure is needed to find a proof in support of the statements. It can be either inference or direct perception.
One can become aware of the consciousness in parts of the body. The unity of consciousness between any part of the body, say an arm, with the consciousness of the mind informs us of the presence of that part even when we have eyes closed and are unable to see it directly. It is possible to directly perceive Consciousness in all its splendor, but to do this one has to withdraw the mind from coming in contact with the external objects and let all thought waves subside to stillness. Even when thought ceases, the feeling of existence remains. In this field of existence, undisturbed by thought in the mind, shines forth the light of Spirit. It appears in the form of self-illuminated ocean of consciousness. It creates a feeling of pure existence.
One can infer that the disturbance caused by the waves of thought prevents visualization of the Spirit within. It also prevents the realization that a human is a spiritual being. Yoga praxis describes the technique that can be used to still the waves in mind and keep them from arising. A calm and quiet mind is an ideal tool to reflect the spiritual light in the field of consciousness. Unless and until that happens, Spirit and spirituality will remain mere words. There would be no way to find what these words actually represent. Take note that the words are used merely to represent an object, a feeling or a reality. Only a personal experience of whatever the word represents makes its meaning clear. At this point, one can adopt the thought-structure of the Vedas and search for the source of the just experienced consciousness. The search ends in the realization of Supreme Consciousness.
But observation isn't the only way to prove the universal nature of consciousness. One can also use inference. People come across many individuals during a day. Ask them if they remember every one they met that day. If they do not, then the next question is: why not? It seems that people become conscious of an object only if their mind comes in contact with it and registers it in memory. In other words, people notice objects only when their mind becomes conscious of it. To be conscious is an act. The subject is the mind, or to be precise, the mental consciousness. It is the mental consciousness that makes the mind becomes conscious of objects. There is thus an entity called consciousness. If the mind becomes conscious of things, there is consciousness within that notices that. The next question is this: is the consciousness within one individual different from the consciousness within another? If the unity of consciousness of the mind with an object is the reason for our knowledge of the object, and if the same object is identified as they really are by two conscious minds, does it not indicate some sort of similarity between the two consciousness? Through such questions and analyses, one infers the existence of spiritual unity between different human beings. One can then say that spiritual understanding leads to unity. Indiscriminate use of the word without real understanding of its meaning may lead to division. It is so because different people may develop different understanding of what it is and insist that their understanding is the correct one. Such attitude could only create conflict. In short, knowledge of the meaning of spirituality brings unity. Mere faith leads to the perception of diversity. Perception of unity results in harmony and peace; and that of diversity results in division, turmoil and conflict.