Through a detailed study of Spinoza's concept of 'experience', Moreau shows how Spinoza extends the power of reason to domains frequently seen as irrational, from common life to history, language to the passions. Where previously Spinoza's thought was identified exclusively with the geometrical method, Moreau demonstrates that by mobilising his unique account of 'experience', Spinoza is able to capture the singularity of individuals, their lives, languages, passions and societies.With readings of each of Spinoza's most famous works, from the Treatise on the Emendation of the Intellect to the Ethics, and also minor writings such as the Hebrew Grammar, Moreau renews our understanding of Spinoza's philosophy by showing us how his geometrical and experiential methods operate simultaneously. Finally, this new vision of Spinoza's philosophy illuminates the enigmatic experience of eternity mentioned in Book V of Spinoza's Ethics.