Three classes of minds.

Hedy Lamarr (1914–2000) — Her work was used by the US navy, and to create Wi-Fi and Bluetooth technologies

The Prince by Niccolo Machiavelli:

… There are three classes of minds:

– one which understands by itself;

– another which appreciates what others understood;

– and a third which neither understands by itself nor through the explanation of others.

The first is the most excellent, the second is good, and the third is useless

The Letters of Machiavelli

Niccolò Machiavelli (Stanford Encyclopedia of Philosophy)

“Machiavelli did not invent ‘Machiavellism’ and may not even have been a ‘Machiavellian’ in the sense often ascribed to him.”