Both Uses of

steadfast
in
Atlas Shrugged

He did not name to himself the nature of his own feeling-never to identify his emotions was the only steadfast rule of his life; he merely felt it-and this particular feeling was pleasurable, which was the only identification he cared to know.†
Chpt 1.9 *

steadfast = firmly consistent

The great man who was so contemptuous-in business-of weaklings who trimmed corners or fell by the wayside, because they couldn't match his strength of character and steadfastness of purpose!†
Chpt 2.3