Since October 7 2023, the war between Israel and Hamas in Gaza has led to public protests against Israel and demands for an immediate ceasefire. In this connection, controversy over antisemitism on campuses across the globe, including Oxford, has intensified. At the heart of the controversy is the definition of antisemitism published by the International Holocaust Remembrance Alliance (IHRA). The definition has been adopted by numerous states and institutions, including Oxford University. The seminar will raise the following issues, among others: What useful role can definitions play in this controversy? Can the IHRA definition perform this role? Is it, in practice, used in a partisan way? Does the Jerusalem Declaration on Antisemitism (JDA) give better guidance? More fundamentally, can a clear line be drawn between antisemitic and non-antisemitic critique of Israel, or is there a deep ambiguity in the phenomenon itself?