The philosopher in question is Alain Finkielkraut, and this is what he said:
https://www.breitbart.com/europe/2019/02/24/french-philosopher-jews-first-victims-of-islamic-immigration/
“French Jewish philosopher Alain Finkielkraut has claimed that the populist movement in Europe has largely been a reaction to demographic changes, blaming German Chancellor Angela Merkel. Finkielkraut labelled Chancellor Merkel’s infamous “wir schaffen das!” (we can do it!) phrase during the height of the migrant crisis in 2015 as “nonsense”, saying, “You see it yourself: you cannot do it. This mix of extreme moralism and economic interests was repugnant,” Die Welt reports. “The Germans wanted to buy themselves free and finally become a morally impeccable people. But that happens at the expense of the Jews, who are the first victims, as more and more immigrants are let in,” he added. Last Saturday Finkielkraut was the victim of anti-semitic abuse hurled at him by a Gilets Jaunes (Yellow Vest) protestor who was later revealed to be an Islamic extremist. Commenting on the attack, Finkielkraut said: “We are now trying to convince ourselves that this is a reawakening of old nationalist and anti-Semitic combat calls such as ‘France belongs to us’, ‘France for the French’.”
“But the one who called that, the most aggressive of them all, is a Salafist,” he said, adding: “If someone says: France belongs to us, then that means: France is destined to become Islamic soil.” France has also seen a surge in anti-Semitic incidents over the past year according to a recently released report. “Modern anti-Semitism is not a game of racism, it is a variant of anti-racism. All anti-Semites today are anti-racists. They speak in the name of humanity, in the name of all suffering beings. And in this way, they associate the Star of David with the swastika,” Finkielkraut observed. He also noted “that anti-Semitism would be a marginal problem in France and Europe if our societies had not been transformed against their will into multicultural societies.”
https://www.breitbart.com/europe/2019/02/21/jewish-population-of-paris-suburbs-rapidly-decreasing/
https://www.algemeiner.com/2019/02/08/we-fled-from-antisemitism-french-jewish-woman-recalls-her-familys-2017-ordeal-in-major-tv-interview/