Sanitation officer: The complaints about the drain in that lane are unfounded; our gang goes there and clears it every Monday morning. Ward member: That the gang goes on Monday nobody doubts. What the residents complain of is the state of the drain on Thursday, and no one from your office has ever looked at it on a Thursday. The ward member's reply proceeds by

The officer proves attendance; the residents complain of condition. The ward member concedes the first in so many words and shows that it does not reach the second, since a drain cleared on Monday may be foul by Thursday. He therefore does not deny the visits, no figures are quoted by either speaker for one to contradict the other, and he proposes nothing — his reply stops at showing the evidence misses the point.