Were Isaac Newton and Jean-Jacques Rousseau alive at the same time?
Yes. Isaac Newton and Jean-Jacques Rousseau were alive at the same time for 14 years, from 1712 to 1727.
Isaac Newton was 69 when Jean-Jacques Rousseau was born.
Jean-Jacques Rousseau was 14 when Isaac Newton died, aged 84.
Isaac Newton
English mathematician and physicist
Born 25 December 1642 (Julian calendar) · died 20 March 1727 (Julian calendar), aged 84
Jean-Jacques Rousseau
Genevan philosopher, writer, and composer
Born 28 June 1712 · died 2 July 1778, aged 66