In the first part of this presentation\, I develop an account of several of the main objections against Aristotle&rsquo\;s principle of non-contradiction that played important parts in the debate at the time of Aristotle&rsquo\;s writing. \;Then\, I reconstruct the main arguments and claims of what I take to be Aristotle&rsquo\;s principal responses to these objections and challenges.
\nIn the second part of the presentation\, I turn to Jan Łukasiewicz&rsquo\; interpretation of the debate between Aristotle and his opponents. \;In particular\, Łukasiewicz argues that Aristotle&rsquo\;s responses to the challenges brought against the PNC reveal an awareness of the weakness of Aristotle&rsquo\;s own position and result in a progressive retreat from the PNC as a universally valid principle of logic and metaphysics towards a much weaker and restricted claim in defense of non-contradiction. \;In conclusion\, I will offer a defense of Aristotle&rsquo\;s responses against Łukasiewicz&rsquo\; criticism and show how a deeper understanding of the positions that challenged Aristotle&rsquo\;s account sheds new light on Aristotle&rsquo\;s overall project of a science of metaphysics and the principle
of non-contradiction.
Keywords: Aristotle\, Łukasiewicz\, Principle of Non-Contradiction\, History of Philosophy