The University of Pennsylvania’s motto comes from a quote from Horace, Leges Sine Moribus Vanae — “Laws without morals are in vain.” But it is a lack of morals, of a willingness to stand up to antisemitism, that has created a “climate of fear” across campus. Demonstrations headed by “Penn Students Against the Occupation,” recognized as an official club by the university, have left students at the Philadelphia-based Ivy League school worried about whether it is a safe environment for learning. Incidents on campus have made it a flashpoint in the debate over how far protests can go.