How did Charles Sanders Peirce evaluate the philosophical importance of John Duns Scotus?

The American philosopher Charles Sanders Peirce held Blessed John Duns Scotus in exceptionally high regard, identifying him as the greatest speculative mind of the Middle Ages and one of the most profound metaphysicians in history.1

Peirce was particularly influenced by the Scotist doctrine of universals, which posits that universal concepts are grounded in a real "common nature" shared by individuals. This principle, which Duns Scotus famously distinguished from the individualizing reality he termed haecceitas (or "thisness"), served as a foundational element in Peirce's own philosophical development. By emphasizing that general types possess a real existence rather than being mere figments of the mind, Duns Scotus provided a framework that resonated deeply with Peirce's work.12