[KhoomeiK]

The 5 non-Vedantic schools were already on the decline long before foreign invasion. I attribute it largely to the Bhakti movement which sort of functioned as the popular wing to the intellectual Vedantic school, which had no parallel in the other Astika schools. Nyaya-Vaisesika arguably survived in the form of Navya Nyaya but never gained popular support while Sankhya-Yoga (and the Buddhist/Sramana milieu) had a lot of their concepts reincorporated into Advaita Vedanta. Mimamsa is completely extinct as far as I know except for perhaps the Srauta tradition in regions of South India. If you want to blame anything for the death of Indian philosophical tradition, blame the onslaught of Vedanta and their relentless arguments about self-god metaphysics for 1500 years.

[raincom]

There are many factors: (a) Prof. Sheldon Pollock notes that there is complete silence in eight domains from 10th century to 15th century. This is due to Islamic Rule.

(b) Bhakti movement did not emerge in the south India. In fact, it is a product of North India in response to Islam. Prof. Jack Hawley made the case for its being North Indian product in his 2015 book.

(c) Prof. SN Balagangadhara in a talk provides another evidence: Bhagavadgita itself notes that gyaana maarga (the research tradition) died out even before the gita time. Upanishads and Brahma sutras were product of this group of researchers (or gyaana maarga).

[z3phyr]

The bhakti movement started in southern part of the subcontinent around 8th century A.D.

The Hephthalite invasions came around 3rd, 4th and 5th century A.D. The Rashidun and Umayad (Islamic campaigns) came around late 600 A.D.

I am not going to talk about the Indo-Greeks, the Indo-Scythians and other invasions, but they happened way before.

[KhoomeiK]

> The bhakti movement started in southern part of the subcontinent around 8th century A.D.

I don't really see how that's relevant. It doesn't matter where the Bhakti movement started, only that it bolstered the Vedantic school's ideas.

> The Hephthalite invasions came around 3rd, 4th and 5th century A.D.

These only really impacted the Punjab region, while the intellectual centers across the Gangetic Plain remained more or less stable as far as I know.

> The Rashidun and Umayad (Islamic campaigns) came around late 600 A.D.

Again, these only really impacted the Sindh and Punjab regions and widespread Islamic conquest only started in the 1200s with the Ghaznavids.

> I am not going to talk about the Indo-Greeks, the Indo-Scythians and other invasions, but they happened way before.

The Indo-Greeks and Scythians arguably had a positive impact on Indian philosophy, pretty much never destroying items with cultural value. They made major contributions to Buddhism and played a significant role in its spread across Asia.

[z3phyr]

Actually, the Hephthalite invasion weakened (and directly led to the fall of) the Gupta Empire which spanned a huge part of the subcontinent.

[raincom]

Prof Jack Hawley of Columbia University convincingly argued the opposite: Bhakti movement did not start in the South, and its a product of North India. Check his book: A Storm of Songs: India and the Idea of the Bhakti Movement (Harvard, 2015)