All the transformation in the universe are brought about by the single principle
Agni or tejas according to the ancient Indian philosophy i.e. darsana. Similarly all the
changes or transformations in the universe are represented by a single term paaka.
The paaka has been defined by in Amarakosa as that which causes parinamana-
conversion of transformation and paravritti- transmutation. Obviously the concept of
paaka is based on the concept of agni (tejas), kaala and dik; the first one being the
primary factor and the remaining two, the contributory factors.
According to nyaya vaiseshika darsana, the paaka is interpreted as
parinamana and paravrtti and these paakas are brought about by the influence of the
Agni or tejas. When an object is brought in contact with tejas, karma is stated to
occur in the ultimate constituent of that object due to abhighata or nodana of tejas.
This karma, in its turn, is held to produce vibhaga, which results in the destruction of
the samyoga that existed between the various constituents of the substrate resulting
in the breakdown into the ultimate particles i.e. paramanus. When these paramanus
are brought in contact with a new group of Agni or tejas, their original gunas undergo
changes. Subsequently, repeated contacts with tejas result in the production of new
gunas, which may entirely differ from the previously existed gunas of the same
paramanus. According to Annambhatta, the kind of paaka is different in each kind of
transformation, i.e. each type of paaka is highly specific in nature. This is referable to
the samyoga and vibhaga that goes on in different kinds of transformations.
The paaka (transformations) is of two types- Pilu paaka and pitara paaka. The
term pilu refers to paramanu and the term pilu paaka refers to the transformations
brought about to the substance at its paramanu level. The destruction and
reconstruction that take place to the bonds between paramanus are responsible for
the transformation in the physical and chemical characters of the substance. The
factors affecting this process are:
1) The nature of constituent substance
2) The intensity of the tejas to which the substance is exposed.
The pitaras are composed of clusters of pilus and hence the term pitara paaka
refers to the changes, which are not so subtle or radical like that occur in pilu paaka.
Whatever may be the condition, the paakas are brought about by the action of tejas
or Agni. The concept of these two types of paaka represents the most fundamental
level of transformation.
The Ayurvedic concepts are evolved in a strong intellectual background of
darsanas. Along with the above-mentioned concept of paaka from the field of
darsanas, Ayurveda texts explain some other types of paaka, which are so important
in the theoretical as well as treatment point of view.
Pachakapitta is the Agni concerned with the building up procedures in the
body. It has 13 divisions. viz. 1 Jataragni, 7 Dhatwagnis and 5 Bhutagnis. The
Dhatu parinama process incorporates the reactions of all these forms of Agni. In
fact, for each dhatu and for each fraction of the dhatu, there is a corresponding Agni.
In other words, every part of the body has its own inherent Agni.
The form of food ready for assimilation is termed as aahara rasa. Samana
vayu transports aahara rasa to hridaya and from hridaya it is circulated all over the
body to reach minute channels which supply nutrition to all the dhatus spread all
over the body. This is influenced by vyana vayu. This aahara rasa is in such a panchabhautik form that any particular dhatu can select its nutrition from it according
to the homogeneity of particles as to suit the panchabhautik composition of each