Ancient India was the abode of intellectuals and great thinkers. With their keen observation and analytical skills, they composed entire treatises on complex subjects like medicine, surgery, anatomy and physiology. This is especially commendable considering the fact that the task was achieved in the absence of sophisticated instruments or gadgets. Yet, the accuracy in figures, descriptions and processes are incredibly similar to those deciphered by recent experts. It is believed that the scholars of yore made systematic careful observations and analyzed things both at gross and subtle levels. By extensive studies on human cadavers, they comprehended the internal makeup of the human body � the knowledge of which guided them in executing surgeries with precision. Owing to their sharp analytical thinking pattern, they could even decode the various physiological processes and define conditions that lead to disturbed functioning. The knowledge contained in Ayurveda, India�s ancient medical system, is the result of their fine observation, thoughtful analysis and apt interpretation. 

Technology has made lives easier for us, thanks to the innumerable contraptions devised by modern day scientists. Technology has touched practically every field, including medicine. The invention of microscope gave a new dimension to the understanding of disease, and approach to treatment. Certain diseases, which baffled people actually originated from tiny organisms or microbes living around us. Further probing revealed that these microbes were present as bacteria and viruses. Further developments in the field of medicine led to the inventions of other diagnostic machines such as the X-Ray, Ultrasound, Magnetic Resonance Imaging, and Computer- sized Tomography. The use of these equipments is directed at confirming and minimizing errors in diagnosis, assisting in surgical procedures, and enhancing treatment. 

An obvious question that arises out of the discussion is the mode of diagnosis adopted by the ancient physicians that led to an enviable success rate in treatment of diseases. Ayurveda physicians of the past espoused the fourfold �tools of knowledge� referred to as �pramana� in Sanskrit. Pramana is defined as: 

"pramiiyate anena iti pramaanam" 

Pramana is a tool through which true knowledge (or knowledge as it is) is achieved. Each school of thought accepts and incorporates different types of pramanas. Ayurveda considers four pramanas as pivotal in diagnosis and treatment, they being � pratyaksa, anumana, aptopadesa and yukti. Pratyaksa and anumana pramanas guide in diagnosis, while aptopadesa and yukti assist in treatment. Pratyaksa in Sanskrit is �direct knowledge�. It is the knowledge generated from the interaction of senses (indriyas) with their objects (arthas). 

"indriyaartha sannikarsajanyam jnaanam pratyaksam" 

(Tarkasamgraha) 

Caraka Samhita, the most respected treatise on Ayurveda defines pratyaksa as: 

"aatmendriya manoarthaanaam sannikarsaat pravartate

vyaktaa tadaatve yaa buddhih pratyaksam saa nirucyate" 

(Caraka Sutra Sthana) 

The knowledge that arises out of the combined effort and interaction between the artha (object), indriya (sense organ), mana (mind) and atma (soul) is called as pratyaksa. In simple words, the sight that we see with our eyes, the sound that we hear with our ears, the odor that we smell through the nose, the touch that we feel with our skin, and the taste that we feel with the tongue are the results of �pratyaksa� pramana. This knowledge, perceived by the sense organs, and unadulterated in any manner is the �truest knowledge� or the pratyaksa. This tool of knowledge is used greatly by a physician in the examination of his patient. For example, visual inspection of symptoms (type of rash, colour of eyes, coating on the tongue), hearing for crepitus in the joints, or feeling the temperature and texture of the skin. 

The second important tool of knowledge is �anumana� which means �inference�. Literally, anumana means the knowledge that is inferred later (anu pascaat miiyate jnaayate iti anumaanam). Anumana pramana is highly useful in areas of unavailability of sufficient information. In such a case, the physician is required to observe the available links and arrive at a conclusion. Anumana spans over three periods of time: the past, the present, and the future. Caraka elaborates further with discreet examples. One can infer the presence of a fire in the neighborhood by looking at smoke. This refers to an inference of the present situation based on an available clue. Deciphering the formation of a fruit (in future) by looking at a seed (today) is another instance of anumana pramana in action. Anumana plays a major role in decoding the etiology of a disease and in diagnosis. 

Aptopadesa, the third tool of knowledge, comprises of two terms. �Apta� means a learned person or a scholar. �Aadesa� means the scholar�s words, preaching or advice. All the theoretical information available in the ancient books as written by the scholarly physicians of the past, based on their vast experience is called as aptopadesa. Before arriving at a conclusion with regard to the diagnosis or treatment of a disease, it is essential to contemplate on the teachings of the seers. For an Ayurvedic physician today, it would mean considering the information available in the major treatises of Ayurveda such as Caraka Samhita and Susruta Samhita to augment diagnosis, and to implement simple treatment measures. 

Caraka considers �yukti� to be the most important tool of knowledge. Yukti may be translated as �analysis�. The inferential knowledge that one arrives at after a careful introspection of various factors is defined as yukti. Caraka cites the following examples. The combined effort and involvement of water (jala), plough (karsana), seed (beeja) and suitable season (rutu) leads to the creation of a plant (sasya). To quote another; the process of churning (manthana) facilitated by an individual (mathya) by means of a torque (manthaana) yields buttermilk (takra). Yukti proves to be an important tool for diagnosis and treatment when there is involvement of multiple dosas, presence of confusing symptoms, and availability of few treatment options due to contradictions in the disease and constitution of the patient. The decision taken by the physician based on his medical knowledge, practical experience, intelligence, observation and analytical skill to formulate an effective treatment is called yukti. 

Contemporary medicine employs interrogation, palpation, percussion and auscultation for examination of patients. This concept is very much in line with the three-step procedure utilized in Ayurvedic diagnostic methods. Referred to as the �trividha pariksa� (trividha � threefold, pariksa � examination), it encompasses darsana (examination by visualization), sparsana (examination by touch) and prasna (interrogation of the patient). Visual examination (darsana) involves a close inspection of the patient for signs and symptoms, and entails sharp observational and interpretational abilities. Examination by touch (sparsana) is beneficial to acknowledge abnormal body temperature, examine swellings, and determine underlying pathology by palpation. Besides, through his healing touch, the physician communicates his concern and assurance to the patient. A thorough knowledge of the disease particulars in the patient�s own words is fundamental for diagnosis. This requires careful interrogation, patient hearing and systematic organization of accrued details. Prasna pariksa in Ayurveda also includes an assessment of the physical and mental constitution (prakriti) ascertained from characteristics, habits and behavior of the patient. Following this, an Ayurvedic physician adopts a holistic approach and prescribes a treatment, which is in synchronization with the patient�s basic nature (prakriti), and concurrently antagonistic to the disease. 

Ayurveda advocates an alternative method of examination of patient called as �astavidha pariksa� (astavidha � eightfold, pariksa � examination), an expanded version of the three-step diagnostic procedure. As the name suggests, it comprises of nadi (pulse), mala (feces), mutra (urine), jihva (tongue), sabda (sound), sparsa (touch), drik (eyes and vision) and akriti (physique and appearance). Contemporary medicine also takes the above factors into consideration in the examination of a patient, with inclusions of blood pressure, heart rate and respiratory rate values. 

A deeper insight into the trividha pariksa and astavidha pariksa confirms their roots in the fourfold tools of knowledge (pramanas). Pratyaksa pramana is the basis for visual and tactile examinations. Anumana pramana is beneficial for reaching a conclusion based on the patient�s contribution of data. Aptopadesa helps to clear ambiguity. Yukti pramana is the vital instrument necessary for arriving at a precise diagnosis and effective treatment strategy. As stated earlier, the treatment should be complementary with the physical and psychological constitution (prakriti) of the patient. Occasionally, there is a contradiction between the patient�s prakriti and the treatment for his ailment. In such cases, the physician is required to adopt a conducive treatment strategy based on his domain knowledge, experience and analytical skills. 

The pramanas proved to be excellent tools of knowledge to the early Ayurvedic physicians, and continue to do so till date. Thus, the ancient physicians, with their high levels of intelligence, and extra ordinary skills of observation, and interpretation achieved intellectual phenomena nthinkable for any modern gadget or contraption.

Source - Mystic India