Which is better, a clock that is right only once a year, or a
clock that is right twice every day? “The latter,” you reply,
“unquestionably.” Very good, now attend.
[Illustration]
I have two clocks: one doesn’t go _at all_, and the other loses a
minute a day: which would you prefer? “The losing one,” you answer,
“without a doubt.” Now observe: the one which loses a minute a day has
to lose twelve hours, or seven hundred and twenty minutes before it is
right again, consequently it is only right once in two years, whereas
the other is evidently right as often as the time it points to comes
round, which happens twice a day.
So you’ve contradicted yourself _once_.
“Ah, but,” you say, “what’s the use of its being right twice a day, if
I can’t tell when the time comes?”
Why, suppose the clock points to eight o’clock, don’t you see that the
clock is right _at_ eight o’clock? Consequently, when eight o’clock
comes round your clock is right.
“Yes, I see _that_,” you reply.
Very good, then you’ve contradicted yourself _twice_: now get out of
the difficulty as best you can, and don’t contradict yourself again if
you can help it.
You _might_ go on to ask, “How am I to know when eight o’clock _does_
come? My clock will not tell me.” Be patient: you know that when eight
o’clock comes your clock is right very good; then your rule is this:
keep your eye fixed on your clock, and _the very moment it is right_ it
will be eight o’clock. “But----,” you say. There, that’ll do; the more
you argue the farther you get from the point, so it will be as well to
stop.