[2] A man of liberal ideas, he was an opponent of the Bourbons, taking part in the riots of 1848.

The following year he published his Manual of Constitutional Law which earned him police persecution and then prison.

[3] In 1860 Pessina fled the Kingdom and resided in Livorno, only to be appointed professor of law at the University of Bologna the following year.

[6][3] In 1899 he became a member of the Accademia dei Lincei[7][8][3] and in 1914 he became President of the Royal Society for the Promotion of the Natural Sciences of Naples.

One of the 229 busts of illustrious Italians that adorn the Pincio promenade in Rome is dedicated to him.