Spinoza opines about Muslims in his Theological-political Treatise:

“In this the Turks have achieved the greatest measure of success. They hold even discussion of religion to be sinful, and with their mass of dogma they gain such a thorough hold on the individual’s judgment that they leave no room in the mind for the exercise of reason, or even the capacity to doubt.”

Turks in Spinoza's Europe would be generally understood as referring to Muslims since the Ottomans were the most influential Muslims in Europe at the time.