Niccolò Machiavell

“As the doctors say of a wasting disease, to start with it is easy to cure but difficult to diagnose; after a time, unless it has been diagnosed and treated at the outset, it becomes easy to diagnose but difficult to cure. So it is in politics. Political disorders can be quickly healed if they are seen well in advance (and only a prudent ruler has such foresight); when, for lack of a diagnosis, they are allowed to grow in such a way that everyone can recognize them, remedies are too late.”
― Niccolò Machiavell, Il Principe