questions from the Communist Manifesto

We read in the Manifesto of the Communist Party that: "It is well known how the monks wrote silly lives of Catholic saints over the manuscripts on which classical works of ancient heathendom had been written. The German literati reversed this process with profane French literature. They wrote their philosophical nonsense beneath the French original. For instance, beneath the French criticism of the economic functions of money, they wrote "Alienation of Humanity," and beneath the French criticism of the bourgeois State, they wrote "Dethronement of the Category of General," and so forth. The introduction of these philosophical phrases at the back of the French historical criticism they dubbed "Philosophy of Action," "True Socialism,"...and so on."

Will someone kindly let me know what do Marx and Engels mean by "over" in italic, "beneath" and "back", "Alienation of Humanity", "Dethronement of the Category of General" and "Philosophy of Action"?