To place Vedic science in context it is necessary to have a proper understanding of the chronology of the Vedic literature. There are astronomical references in the Vedas which recall events in the third or the fourth millennium B.C.E. and earlier. The recent discovery (e.g. Feuerstein 1995) that Sarasvati, the preeminent river of the Rigvedic times, went dry around 1900 B.C.E. due to tectonic upheavels implies that the Rigveda is to be dated prior to this epoch, perhaps prior to 2000 B.C.E. since the literature that immediately followed the Rigveda does not speak of any geological catastrophe. But we cannot be very precise about our estimates. There exist traditional accounts in the puranas that assign greater antiquity to the Rigveda : for example, the kaliyuga tradition speaks of 3100 B.C.E. and the Varahamihira tradition mentions 2400 B.C.E. According to Henri-Paul Francfort (1992) of the Indo-French team that surveyed this area, the Sarasvati river had ceased to be a perennial river by the third millennium B.C.E., this supports those who argue for the older dates.
No comprehensive studies of ancient Indian science exist. The textbook accounts like the one to be found in Basham’s The Wonder that was India are hopelessly out of date. But there are some excellent surveys of selected material. The task of putting it all together into a comprehensive whole will be a major task for historians of science.
This essay presents an assortment of topics from ancient Indian science. We begin with an outline of the models used in the Vedic cognitive science; these models parallel those used in ancient Indian Physics. We also review mathematics, astronomy, grammar, logic and medicine.
Vedic Cognitive Science
The Rigveda speaks of cosmic order. It is assumed that there exist equivalences of various kinds between the outer and the inner worlds. It is these connections that make it possible for our minds to comprehend the universe. It is noteworthy that the analytical methods are used both in the examination of the outer world as well as the inner world. This allowed the Vedic rishis to place in sharp focus paradoxical aspects of analytical knowledge. Such paradoxes have become only too familiar to the contemporary scientists in all branches of inquiry (Kak 1986).
In the Vedic view, the complementary nature of the mind and the outer world, is of fundamental significance. Knowledge is classified in two ways: the lower or dual; and the higher or unified. What this means is that knowledge is superficially dual and paradoxical but at a deeper level it has a unity. The Vedic view claims that the material and the conscious are aspects of the same transcendental reality.
The idea of complementarity was at the basis of the systematization of Indian philosophic traditions as well, so that complementary approaches were paired together. We have the groups of: logic (nyaya) and physics (vaisheshika), cosmology (sankhya) and psychology (yoga), and language (mimamsa) and reality (vedanta). Although these philosophical schools were formalized in the post-Vedic age, we find an echo of these ideas in the Vedic texts.
In the Rigveda there is reference to the yoking of the horses to the chariot of Indra, Ashvins, or Agni; and we are told elsewhere that these gods represent the essential mind. The same metaphor of the chariot for a person is encountered in Katha Upanishad and the Bhagavad Gita; this chariot is pulled in different directions by the horses, representing senses, which are yoked to it. The mind is the driver who holds the reins to these horses; but next to the mind sits the true observer, the self, who represents a universal unity. Without this self no coherent behaviour is possible.
The Five Levels
In the Taittiriya Upanishad, the individual is represented in terms of five different sheaths or levels that enclose the individual’s self. These levels, shown in an ascending order, are :
The physical body (annamaya kosha); Energy sheath (pranamaya kosha); Mental sheath (manomaya kosha); Intellect sheath (vijnanamaya kosha); Emotion sheath (anandamaya kosha)
These sheaths are defined at increasingly finer levels. At the highest level, above the emotion sheath, is the self. It is significant that emotion is placed higher than the intellect. This is a recognition of the fact that eventually meaning is communicated by associations which are influenced by the emotional state.
The energy that underlies physical and mental processes is called prana. One may look at an individual in three different levels. At the lowest level is the physical body, at the next higher level is the energy systems at work, and at the next higher level are the thoughts. Since the three levels are interrelated the energy situation may be changed by inputs either at the physical level or at the mental level. When the energy state is agitated and restless, it is characterized by rajas; when it is dull and lethargic, it is characterized by tamas; the state of equilibrium and the balance is termed sattva.
The key notion is that each higher level represents characteristics that are emergent on the ground of the previous level. In this theory mind is an emergent entity, but this emergence requires the presence of the self.
The Structure of the Mind
The sankhya system takes the mind as consisting of five components : manas, ahankara, chitta, buddhi, and atman. Again these categories parallel those of Figure 1.
Manas is the lower mind which collects sense impressions. Its perceptions shift from moment to moment. This sensory-motor mind obtains its inputs from the senses of hearing, touch, sight, taste and smell. Each of these senses may be taken to be governed by a separate agent.
Ahankara is the sense of I-ness that associates some perceptions to a subjective and personal experience.
Once sensory impressions have been related to I-ness by ahankara, their evaluation and resulting decisions are arrived at by buddhi, the intellect. Manas, ahankara, and buddhi are collectively called the internal instruments of the mind.
Next we come to chitta, which is the memory bank of the mind. These memories constitute the foundation on which the rest of the mind operates. But chitta is not merely a passive instrument. The organization of the new impressions throws up instinctual or primitive urges which create different emotional states.
This mental complex surrounds the innermost aspect of consciousness which is called atman, the self, brahman, or jiva. Atman is considered to be beyond a finite enumeration of categories.
All this amounts to a brilliant analysis of the individual. No wonder, this model has continued to inspire people around the world to this day.