A conductor can easily get into bad habits. He knows, for instance, that such practices as
looking down at the score relentlessly
using two hands continually and thoughtlessly
dividing the beat gratuitously
. . . are rarely helpful, but he does these things anyway. Being accountable to no one, he chooses to go his own way, avoiding even the self-critique that could come from reviewing video. The conductor who knows what to do but doesn’t do it has simply gotten into lazy habits.
So whoever knows what is good to do and does not do it….
– James 4:17, NET Bible, referring particularly to individual presumption