“Indifference and ignorance are clearly a form of egoism that is only self-oriented. In some cases, it has the potential to deny conscience and even go against human dignity.”
Related quotes

“Indifference of every kind is reprehensible, even indifference towards one’s self.”
Source: Aphorisms (1880/1893), p. 82.

Letter to three students (October 1967) as translated in Solzhenitsyn: A Documentary Record (1970) edited by Leopold Labedz (1970) “The Struggle Intensifies".

RTNDA Convention Speech (1958)
Context: This instrument can teach, it can illuminate; yes, and even it can inspire. But it can do so only to the extent that humans are determined to use it to those ends. Otherwise it's nothing but wires and lights in a box. There is a great and perhaps decisive battle to be fought against ignorance, intolerance and indifference. This weapon of television could be useful.
Stonewall Jackson, who knew something about the use of weapons, is reported to have said, "When war comes, you must draw the sword and throw away the scabbard." The trouble with television is that it is rusting in the scabbard during a battle for survival.
Philosophy and Real Politics (2008).
Philosophy and Real Politics (2008)