This quote was attributed to Epimenides – himself a Cretan. Wait a minute: if his statement is correct than as a Cretan he must be lying – therefore his statement must be incorrect. But the statement can’t be both correct and incorrect, it is a logical loop.
Some logic problems like this are quite hard. Here is another one, not so difficult.
“Growth will require the investment of more money in the company”
“We need growth therefore we should invest more money in the company”
They look the same, and a surprising number of business people think they are the same. However Investment without a clear plan can do the opposite – loading a company with Debt which can’t be repaid.
Bob Browning's blog 
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