From The Attention Merchants:
Any communication, Lippmann came to see, is potentially propagandistic, in the sense of propagating a view. For it presents one set of facts, or one perspective, fostering or weakening some “stereotype” held by the mind. It is fair to say, then, that any and all information that one consumes—pays attention to—will have some influence, even if just forcing a reaction. That idea, in turn, has a very radical implication, for it suggests that sometimes we overestimate our own capacity for truly independent thought. In most areas of life, we necessarily rely on others for the presentation of facts and ultimately choose between manufactured alternatives, whether it is our evaluation of a product or a political proposition. And if that is true, in the battle for our attention, there is a particular importance in who gets there first or most often. The only communications truly without influence are those that one learns to ignore or never hears at all; this is why Jacques Ellul argued that it is only the disconnected—rural dwellers or the urban poor—who are truly immune to propaganda, while intellectuals, who read everything, insist on having opinions, and think themselves immune to propaganda are, in fact, easy to manipulate.