<p>Australia’s large private school sector receives high levels of public funding, has a high and increasing share of enrolments and advantaged students, and a decreasing share of disadvantaged students. Employing an historical sociology approach and drawing on primary and secondary sources, I argue that this ascendency arose from the inherent differences between public and private schooling, combined with the historical circumstances as schooling developed from early colonial times. Inherent differences include public schooling’s responsibilities to the whole community and the private sector’s freedoms and responsibilities only to its chosen clienteles and its politically powerful auspicing organisations. I clarify what private school ascendency means, build on my own and others’ arguments about residualisation, and explain my use of the terms positional goods and sector blind. Particularly, I show that sector blind policies fail to account for the role of the private sector’s freedoms and the public sector’s responsibilities regarding the teaching labour market and numerical and qualitative enrolments. I conclude with some brief suggestions about what can be done.</p>