One troubling thing in the Dharma that I’ve heard about a bit is the whole “Hiniyana vs. Mahayana” difference, which is usually seen as Mahayana literature spelling out why the Hiniyana (literally, “Lesser Vehicle”) is so inferior. I personally think the differences and dividing lines are WAY overblown. Drikung Kagyu founder Lord Jitgen Sumgon said that all the three turnings of the wheel of Dharma contain each of the others, so all of them – Hiniyana, Mahayana, and Vajrayana – are mixed together in a way that makes them impossible to extract.
I got these quotes from the Pali Canon – the scriptures used by Theravadans of Southeast Asia – from Douglas Duckworth, an excellent translator that has been up at TMC in Frederick several times in the last few years.
These words of the Buddha do seem to more than imply the presence of Buddha-nature – Thagatagharba – the underlying nature of enlightenment in all living beings. That is generally seen as the core teaching of the “Third Turning of the Wheel of Dharma”, which is most often associated with Vajrayana (since it is required in order to explain how Vajrayana ‘works’).
“The great light of the self (attâ/atma) is the great-self (mahâtman) which is an illumination beyond the physical (rûpa). The great-self is similar to the solar sphere as the source of the sphere’s brightness, as such, the radiant power.”— Vimanavatthu Atthakatha No. 268
“The Tathâgata is the true reality of the self (attâ).” — Majjhimapannasa Atthakatha 3.379
The true nature (bhâva) of the Tathâgata is the self (attano). — Itivuttaka Atthakatha 2.187
“The Blessed One (bhagavat) is the origin of his lineage, [which is] the great perfection (mahâsammâ).” — Mahâvagga Atthakatha 2.677
“What is external (parato) is empty (suññato), is inanimate (anatta), is the mark of the inanimate (anattalakkana).” — Majjhimapannsapali Atthakatha 3.146
“The vision of perfection of the path of the self (maggatta).” — Patisambhidamagga Atthakatha 3.608
“The self’s perfection (sammattâ) is the Noble Eightfold Path.” — Nettippakarana Atthakatha No.184
“The self is deathless (amara) and is identical with one’s true nature (sabhâva).” — Jataka Atthakatha No. 6 6.370
“The Tathagata is the Buddha, and the self.” — Itivuttaka Atthakatha 2.187
“Samsara is samsara as non-immortal faring. Awareness of the immortal supreme self is the faring of the immortal supreme self.” — Therigatha Atthakatha 289
“Just so it is that the self (attâ) is none of the five aggregates (Skt., skandha).” — Udana Atthakatha No. 376
“The one self, the one true reality (ekabhâva), is without emptiness (asuññata).” — Uparipannasapali Atthkatha 4.151