Thinking cap approved by the Catholic Church

Explanation: During the medieval period, several Muslim polities became prominent and culturally influential - amongst them, Al-Andalus (Muslim-ruled Spain), Sicily, and Palestine; all Muslim-ruled regions with large non-Muslim populations. (North Africa too, though the meme doesn’t mention it)

In all three, a greater level of religious toleration was afforded other faiths than in traditional Christian polities - Islam had formed both religiously and politically in an environment where other monotheistic faiths (which also demanded exclusive loyalty) were well-established. Islam, thus, had to formulate rules for dealing with stubborn non-converts from the very start (broadly speaking, the rule being ‘tax them extra but otherwise leave them to their own devices’).

In addition to being less repugnant to modern morals and cultural norms than the largely intolerant practices of medieval Christian Europe, it also made those Muslim polities - Al-Andalus in particular - attractive to free thinkers and other religious dissidents, who contributed to a lively tradition of cultural and academic excellence. Christians, Jews, and Muslims largely lived together and formed social and economic bonds to a degree that baffled most of Christian Europe - why would the FAITHFUL consort with HEATHENS like they’re human beings!?

When the Christian Normans conquered Sicily, they would actually return the favor for a time - Muslims were allowed to continue practicing their faith in exchange for a tax (a level of toleration nearly unheard of in other Christian Catholic polities) and to resolve their disputes according to their own religious laws. Unfortunately, as Norman Sicily became more integrated with the power structures of Christian Europe, that tolerance faded away.