He made a step back and said in a strange tone of dispassionate wonder, "We're a couple of blackguards, aren't we?"
"We haven't any spiritual goals or qualities. All we're after is material things. That's all we care for."
She looked at him, unable to understand. But he was looking past her, straight ahead, at the crane in the distance. She wished he had not said it. The accusation did not trouble her, she never thought of herself in such terms and she was completely incapable of experiencing a feeling of fundamental guilt. But she felt a vague apprehension which she could not define, the suggestion that there was something of grave consequence in whatever had made him say it, something dangerous to him. He had not said it casually. But there had been no feeling in his voice, neither plea nor shame. He had said it indifferently, as a statement of fact.
Then, as she watched him, the apprehension vanished. He was looking at his mills beyond the window; there was no guilt in his face, no doubt, nothing but the calm of an inviolate self-confidence.
"Dagny" he said, "whatever we are, it's we who move the world and it's we who'll pull it through."
[Atlas Shrugged, Ayn Rand, p. 87-88]
Dagny senses Hank's error, but does not see it clearly until later in the novel. They were not simply materialists. They were spiritual. Not in the religious sense, but spiritual with respect to one's own life.
The same kind of measurement guides man’s actions in the wider realm of moral or spiritual values. (By “spiritual” I mean “pertaining to consciousness.” I say “wider” because it is man’s hierarchy of values in this realm that determines his hierarchy of values in the material or economic realm.) But the currency or medium of exchange is different. In the spiritual realm, the currency—which exists in limited quantity and must be teleologically measured in the pursuit of any value—is time, i.e., one’s life.
[Introduction To Objectivist Epistemology, Ayn Rand, p. 33]