Telling people not to have children is unthinkable and inhumane.
Human morality is unthinkable without empathy.
It is simply unthinkable that we will ever again send overseas a great expeditionary force of armed men.
That," he whispered, "is unthinkable." In Mosca’s experience, such statements generally meant that a thing was perfectly thinkable, but that the speaker did not want to think it.
My weight fluctuated when I was 30, and I did the unthinkable - I stepped out as a plus-sized model.