He subsequently graduated from the University of Sydney with first-class honours in English literature and philosophy[5] whilst studying with a view to become a secondary-school teacher.

Upon his return to Australia he took up a post at the Institute of Advanced Studies at the Australian National University, where he was professor of Philosophy in the Research School of Social Sciences from 1958 to 1979.

[7] Philosopher Frank Jackson notes that Passmore "shaped public debate and opened up philosophy and history of ideas to the wider world".

[7] In his book Man's Responsibility for Nature (1974)[9] Passmore argued that there is urgent need to change our attitude to the environment, and that humans cannot continue unconstrained exploitation of the biosphere.

However, he rejected the view that we need to abandon the Western tradition of scientific rationalism, and was unsympathetic towards attempts to articulate environmental concern through radical revisions of our ethical framework, as advocated by deep ecologists, which he conceived as misguided mysticism or irrationalism.