In the second half of 1944, Jean-Paul Sartre wrote an essay entitled 'Anti-Semite and Jew'. He analyses what might be termed the moral pathology of the anti-Semite. Such a person, Sartre suggests, has chosen to enact a passion, a passion of hatred. The motive is the desire for 'impenetrability' -- a disavowal of reasoned argument -- and a pleasure taken in the assertion and re-assertion of what is known to be false. Sartre's essay was written hurriedly and looking back over 70 years, we can see its flaws. But I suggest that the kernel of his analysis of the anti-Semite is compelling, especially in the context of the growth of anti-immigrant prejudice in the UK and elsewhere. Using Sartre as a starting point, I discuss the nature of prejudice and suggest that to counter prejudices, a civic education is needed that emphasises a narrative of liberty.