Locke’s empirically-based account of the mind (like his good friend Newton’s of the physical universe) was a corner-stone of the Enlightenment. His acquaintance and scientific mentor Boyle probably introduced Descartes’ ideas to him; he in turn influenced Rousseau and Voltaire. Wren, Hooke and Dryden were fellow school-students. He was closely involved with the experimentalist group around John Wilkins in Oxford – Willis, Lower and Wren, and Boyle and his assistant Hooke, were members. Huygens confirmed the soundness of Newton’s maths for him; Wycherley was a close friend. Locke told Boyle that miners’ “terrible apprehensions” stopped him getting his barometer underground.