Vajrasuci (Siddhacarya Ghoshapada) 27

27

(ja) ataḥ smṛtiprāmāṇyānmanyāmahe24 jātistāvad brāhmaṇo na
bhavati
(jha) atha manyase mātā vā'brāhmaṇī bhavet | teṣāṃ pitā brāhmaṇastato
brāhmaṇo bhavatīti| yadyevaṃ dāsīputrā api brāhmaṇajanitā brāhmaṇā bhaveyuḥ
na caitadbhavatāmiṣṭam
(ña) kiṃ ca| yadi brāhmaṇaputro brāhmaṇastarhi brāhmaṇābhāvaḥ prāpnoti
idānīntaneṣu brāhmaṇeṣu pitari sandehād| gotrabrāhmaṇamārabhya brāhmaṇīnāṃ
25śūdrābhigamanadarśanād| ato26 jātirbrāhmaṇo na bhavati

(h) Therefore, from the authority of Smṛti, we consider that birth is not the brāhmaṇa.
(i) Now you might think: 'The mother may well not be a brāhmaṇa woman, [yet] their father was a brāhmaṇa, and therefore one becomes a brāhmaṇa.' If so, even the sons of female slaves fathered by a brāhmaṇa would be brāhmaṇas, but this is not accepted by you.
(j) Moreover, if a brāhmaṇa's son is a brāhmaṇa, then there would result the non-existence of brāhmaṇas, because of doubt regarding the father among present-day brāhmaṇas, since brāhmaṇa women, beginning from the clan-brāhmaṇa, are seen going to śūdras. Therefore, birth is not the brāhmaṇa.