Were the Enlightenment thinkers "aggressively atheist"? A few of them were (e.g. Baron d'Holbach), but the majority were not. Locke recommended toleration and argued that the care of the souls should not be committed to the civil magistrate, because "true and saving religion consists in the inward persuasion of the mind, without which nothing is acceptable to God." Newton believed that Harmony in the System was an argument for a Deity. Montesquieu thought it a good thing to have several religions in a State. Voltaire was against fanaticism and superstition (as all Enlightenment thinkers were) but was not against religion as such, which, according to him, "exists to keep mankind in order, and to make men merit the goodness of God by their virtue." Rousseau was a Deist, certain "that the whole universe is one design, and sufficiently displays one intelligent agent," who regulates it to preserve "the present and established order of things." Jefferson called for toleration, but he said he was a Christian. So did Franklin and Paine.
In other words, the title of Kant's book on religion _Religion within the Boundaries of Mere Reason_ seems to describe the dominant attitude of the Enlightenment thinkers.
Hobbes, Machiavelli, and Marx constitute a minor strain of materialism in the modern Western philosophy.
Yoshie