Necessitous men are not, truly speaking, free men, but, to answer a present exigency, will submit to any terms the crafty may impose upon them.

Robert Henley (1708–1772), English jurist, politician; 1st Earl of Northington, Lord High Chancellor of Great Britain (1761–67)

Vernon v. Bethell, 28 Eng. Rep. 838, 839 (Ch. 1762)
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The case was about a deeply indebted man (Vernon) who agreed to unfair terms in securing a loan against his Antigua sugar plantation from a wealthy customer (Bethell). Henley ruled that Vernon was in such dire financial straits that he was not truly free to negotiate a fair contract.

For more about the court case see here and here.

The core phrase here was adopted by Franklin Roosevelt is some of his speeches, extending the context from contract law to the social contract.