Immanuel Kant (c. 1724-1804)
“Logic cannot have any empirical part; that is, a part in which the universal and necessary laws of thought should rest on grounds taken from experience; otherwise it would not be logic; i.e., a canon for the understanding of the reason, valid for all thought, and capable of demonstration.”
- From the Fundamental Principles of the Metaphysic of Morals (Preface) by Immanuel Kant (c. 1724-1804). The translation is by Thomas Kingsmill Abbott (d. 1913), republished by The Great Books Foundation (1949).