Leoni died prematurely (aged 54) in Alpignano, under tragic circumstances, killed in 1967 by Osvaldo Quero.

For Leoni, liberty consists of keeping the lives of people and the resources they command out of the political sphere as much as possible.

[5] Leoni believes that, in the long run, a system centred on legislation is fundamentally incompatible with the maintenance of a free society.

Partly, this is because of the inherent temptations that legislation provides for rent-seekers and other parties seeking to oppress or plunder non-consenting losers in the political process.

[7] Leoni’s thought had a strong impact on important thinkers like James M. Buchanan, Friedrich von Hayek, Murray N. Rothbard and Gordon Tullock.