I'm reading John Wyndham's The Chrysalids, and I noticed this:
quote:
It was perplexing to know whether the time had not come when we ought to get rid of the tell-tale great-horses - perhaps drive them on along the track while we made off in a different direction on foot. The decision was difficult to make without more information.
I don't see how the presence or absence of that not makes any difference to the meaning. Similar to these sentences.
