1. Painting a very broad brush, as in half of Eurasian philosophy, check out Chakravarthi Ram-Prasad's 'Eastern Philosophy' [1].

2. More technical, but a valuable introduction to analytic methods in classical Indian thought: Jonardon Ganeri's 'Philosophy in Classical India: An Introduction and Analysis' [2]

These are, of course, scholars writing in a scholarly vein. Two books about Guru figures with deep spiritual experience are:

3. Sri Ramakrishna Kathamrita, translated into English as 'The Gospel of Sri Ramakrishna'[3]

4. Talks with Sri Ramana Maharshi [4]

Finally, to take a comparative route:

5. Roberto Calasso's 'Ka' which is his take on the Vedic-Puranic-Itihasic Corpus as a whole [5].

and to understand how India meets Greece via Persepolis and Egypt:

6. Thomas McEvilley's 'Shape of Ancient Thought' [6]

[1] https://www.amazon.com/Eastern-Philosophy-Dr-Chakravarthi-Ra...

[2] https://www.amazon.com/Philosophy-Classical-India-Introducti...

[3] https://www.amazon.com/Gospel-Sri-Ramakrishna-Swami-Nikhilan...

[4] https://www.amazon.com/Talks-Ramana-Maharshi-Realizing-Happi...

[5] https://www.amazon.com/Ka-Stories-Mind-Gods-India/dp/0679451...

[6]https://www.amazon.com/Shape-Ancient-Thought-Comparative-Phi...

Kerala in particular and South India more generally has also preserved other Indian knowledge traditions well - Ayurveda comes to mind.

But despite my innate Indian nationalism I think the time has come to stop writing articles (or even having thoughts) like the one linked above.

Yes, many cultures, including several represented in the Indian subcontinent, had deep and important ideas. It's even likely that in some disciplines - the mind sciences being the most obvious - there are many ideas and practices that are waiting to transform and revolutionize 'western' science, whatever that might mean.

But the knee jerk chauvinistic instinct that says all science (& democracy & sliced bread) arose in Greece and the Indian/Chinese/Middle-Eastern response to counter that with continued fractions in the Lilavati (as well as spaceships and chimeras) has run its course in my view. Plain common sense and generosity suggests that insights have mingled across people's for millennia. One of my favorite sources for that belief: Thomas McEvilley's superlative "Shape of Ancient Thought." [1]

If anything, the events of the past weeks show that we are still stuck in a parochial mindset when the big problems of the present and the foreseeable future are all human in the expansive sense of that term. And why human - I would rather rather we started thinking with any number of other species that have something to teach us.

[1] https://www.amazon.com/Shape-Ancient-Thought-Comparative-Phi...

I've heard Thomas McEvilley mentioned as a good source for the link between pre-Socratic philosophy and India.

https://www.amazon.com/The-Shape-Ancient-Thought-Philosophie...