Full Idea
Doing the unthinkable causes deep, often irreparable, damage to our sense of ourselves. ...That is why the unthinkable indicates a more basic commitment than what we have to any value.
Gist of Idea
Doing the unthinkable damages ourselves, so it is more basic than any value
Source
John Kekes (The Human Condition [2010], 03.3)
Book Reference
Kekes,John: 'The Human Condition' [OUP 2010], p.61
A Reaction
Kekes makes the interesting claim that what is unthinkable is so basic that it doesn't even count as a value - it is more like a fact of your own nature, which is prior to your values. Not sure about that.
Related Idea
Idea 64 There is no right time or place or way or person for the committing of adultery; it is just wrong [Aristotle]