One can distinguish four crucial contributions which the Indian civilisation can make to science, and more particularly to psychology.
Its earliest formulations can be found in some of the oldest Indian texts like the Ṛg Veda, the early Upaniṣads and the Bhagavad Gītā. The "Vedic paradigm" given in these texts functions like a loving grandmother to the enormous variety of spiritual, philosophical, religious and cultural schools which India later brought forth. Outside India, it has been mainly these later traditions that have made an impact. One can think for example of the Buddhist meditation techniques that have spread since millennia throughout Asia and in more recent times in Europe and the Americas and the "eightfold path" described in Patanjali's Yogasutras wich became popular amongst practitioners of hatha-yoga. There is an extensive body of research about them, and there can be no reasonable doubt about their value for self-development and therapy.
The older, more integral tradition is interesting for a different reason. It is its ability to support and nurture in an impartial (and often surprisingly modern) manner, the entire range of human efforts at understanding and improving the world and ourselves, whether religious, cultural, spiritual, or scientific. As science and technology are removing the distances that used to keep people and cultures apart, it is hard to exaggerate how much humanity needs such an integral framework for understanding all aspects of reality, and all the different ways in which people deal with them.
In modern times, Sri Aurobindo is the main exponent of the integral Indian tradition. We will discuss Sri Aurobindo's take on the Vedic understanding of reality in the next chapter.
These first two alone -- the Indian understanding of the basic nature of reality and knowledge, together with the practical methods for the study of the subjective domain that followed from there -- could revolutionise psychology and its applications in education, self-development, counselling, therapy, management, etc.
We will look at the epistemology and methodology in Part Three, "How do we know?".
One of the neat outcomes of the Indian approach is that it provides a logically coherent map of human nature in all its complexity, including things that are entirely beyond the scope of present day mainstream psychology.
Psychological theories and models will be taken up in Part Two, "Who am I?", and in Part Four, "Meeting others and the world".
As mentioned earlier, decontextualised versions of two of these, hathayoga exercises and mindfulness, are already adopted by mainstream psychology, and more comprehensive implementations are part of a variety of subcultures, but while all this is great for those who use them, it is not enough to take psychology further as a science. For that we need also to understand the first two contributions, the ontology and epistemology that gave rise to them.
We will explore a variety of such techniques for inner change and development together with the underlying theory in Part Five, "Working on oneself", and in Part Six, "Working with others".
Studying the Indian tradition is however, not that simple. The Indian civilisation is extremely complex and so, if one wants to go beyond the usual platitudes, one has to choose between a selection and a synthesis. For one's own individual growth, a selection may well be the most efficient way to proceed, but since each Indian system has specialised in a different aspect of human nature, if we want to develop a comprehensive framework for the whole of psychology, what we need is a synthesis. Instead of attempting to make my own, for which I am ill-equipped, I've used for this text, the synthesis Sri Aurobindo made in the first half of the last century. In the next chapter we'll have a look at his work.