Perfect is the enemy of good


Perfect is the enemy of good, or more literally the best is the enemy of the good, is an aphorism which is commonly attributed to Voltaire, who quoted an Italian proverb in his Dictionnaire philosophique in 1770: "Il meglio è l'inimico del bene". It subsequently appeared in his moral poem , which starts
Aristotle, Confucius, and other classical philosophers propounded the principle of the golden mean, which counsels against extremism in general. The Pareto principle or 80–20 rule explains this numerically. For example, it commonly takes 20% of the full time to complete 80% of a task while to complete the last 20% of a task takes 80% of the effort. Achieving absolute perfection may be impossible and so, as increasing effort results in diminishing returns, further activity becomes increasingly inefficient.
Robert Watson-Watt, who developed early warning radar in Britain to counter the rapid growth of the Luftwaffe, propounded a "cult of the imperfect", which he stated as "Give them the third best to go on with; the second best comes too late, the best never comes."