Avasenna's Logic

Avasenna effectively replaced Aristotle as the author whom most personified philosophy. Avasenna's respect for and use of his predecessors from Aristotle onwards didn't prevent him from putting forth innovative ideas in logic. Some of Avasenna’s influential ideas in logic have to do precisely with the modal notions I've been discussing, necessity, contingency, and impossibility. We even saw modality turning up in his epistemology, when he said that knowledge in the strict sense must involve necessary truths.