Final answer:
Montesquieu is the likely Enlightenment thinker who said the quote.
Step-by-step explanation:
The Enlightenment thinker who likely said the quote 'It is necessary from the very nature of things that power should be a check to power' is Montesquieu. Montesquieu was a French philosopher known for his theory of the separation of powers, which influenced the political systems of many countries.
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