The Animal Psyche, the essay by Piero Martinetti that we propose to our readers today, was the subject of a lecture given by the philosopher in 1920 at the Milanese Society for Philosophical and Religious Studies. Both in this text and in another later one, Compassion Toward Animals, Martinetti argued that animals, just like human beings, possess intellect and consciousness, and that therefore ethics must not be limited to the regulation of inter-human relations but must also necessarily extend to seeking well-being and happiness for all those sentient forms of life (i.e., those provided with a nervous system) which, like man, are capable of feeling joy and pain.