In hoary past, the intellectual class of Bharat had done tremendous search for knowing the supreme reality. Their observations have been recorded in the Vedas. Vedas are said to be the eternal truths revealed by Supreme Being to the Risis. The word Risi means a seer, from the root drisi, to see. So the Risi is the Mantra-Drasta, a seer of mantra or thought and not Karta, creator. The Risis saw the truth or heard them. So, the Veda is also called Sruti, that which is 'heard' or 'revealed'. The Risis are not the authors of the mantras with which their names are associated. They were the seer of the thought, which existed already. The Vedas are Apauruseya (of super-human origin).
Patanjali analysed the various states of highly attained intellectual consciousness of man. Apart from empirical knowledge, he described Ritambhara prajn, the truth bearing intellect; Pratibham, the intuitive knowledge; Vivekaja jnana intuitional discrimination; Taraka Vivekaja jnana; simultaneous, immediate and omni-objective knowledge. Our Risis attained the highest empirical knowledge as well as the intuition of these categories. This is why they were capable to penetrate the mystery of the Vedas and to search out various branches of science.
The knowledge gained transforms into wisdom. The aspirant realizes the context in which a particular thought, concept, and action evolves and what it will achieve. He / She enters into a realm of infinite intuition – by which he / she can see the future and the past, moreover, he / she becomes increasingly aware of how things will shape even under the influence of minutest action – an awareness level that can perceive the subtle changes and ripples produced by the emergence of thought or action.
The sources of a scientific knowledge in the present age is derived from information processed through a systematic series of analytical methods, experimentation and observations. This holds true, especially for the medical science / life science besides other. It primarily revolves around the fact that medical truths can be formulated only after a thorough understanding of the underlying physiological processes. Experimentation is the key tool, here. Experiments that focuses on using the senses of the observer, especially sight. It is thus the 'what I see is what I believe' factor that runs the entire experimentation and finalisation of modern medical statements on human physiology.
This was not the case with the Vedic science – medicine / Ayurveda. As far as Vedic science is concerned, its origin is attributed to the soul based infinite intuition or realisation.
It has been held that intuition is a means of knowledge that is distinguishable very clearly from the knowledge derived by senses or reasoning or by analogy. The knowledge derived by intuition is not only by direct but it spring from the identity of the subject and the object, which are related to each other in the process of knowledge. This process does not need to depend upon the exercise of the sense. This knowledge sees even when the eyes are closed; it hears even where ears are sealed. Again, this knowledge is not ratiocinative. It does not strive to arrive at a conclusion on the basis of premises and by the help of some universal principles. This knowledge is immediate; there are no premises in this process. The conclusions are themselves the states of experience intimately identical with the objects of knowledge. Finally, this knowledge is not open to fallacies, doubts or errors, since these deficiencies belong to to senses or to the process of reasoning. The intuitive knowledge is, therefore, regarded as authentic and true. Just as the light of the sun can be proved only through light itself, even so the light of this knowledge can be proved through this very light. This knowledge is, therefore, also known as svayam prabha, self-luminous.
Ayurveda (life science) is considered as the Upaveda of Atharvaveda. According to Susruta, Ayurveda is auxiliary text of Atharvaveda. In this original form it had one thousand chapters containing total one lakh slokas and Brahma composed it prior to the creation of this universe. The fundamental principles of the science of medicine, including the tridosa concepts, saptadhatu concepts, the concept of digestion and metabolism, anatomical descriptions and descriptions of several diseases are available.
Ayurveda accepts concentrated meditation and intuition (yoga) as the method of acquiring knowledge. Moreover, an ancient social philosopher scientist, Gautama Aksapada had established certain basic principles for research and investigation in any subject in the form of Nyaya Sutras (Nyaya means analysis; it is the science of precise thinking). According to Nyaya Sutras, there are four steps in the method of establishing the true identity of a fact, a phenomenon or an object. These are pratyaksa (perception), anumana (inference), upamana (comparison) and aptavakya (statement by an expert).
Ref: Vedic Microbiology By Dr. Chakradhar Frend 'Anjista'; Dr. Shriji Kurup