Largely non-religious, Heinrich was a man of the Enlightenment, interested in the ideas of the philosophers Immanuel Kant and Voltaire. A classical liberal, he took part in agitation for a constitution and reforms in Prussia, which was then an absolute monarchy. In 1815, Heinrich Marx began working as an attorney and in 1819 moved his family to a ten-room property near the Porta Nigra. His wife, Henriette Pressburg, was a Dutch Jewish woman from a prosperous business family that later founded the company Philips Electronics. Her sister Sophie Pressburg (1797–1854) married Lion Philips (1794–1866) and was the grandmother of both Gerard and Anton Philips and great-grandmother to Frits Philips. Lion Philips was a wealthy Dutch tobacco manufacturer and industrialist, upon whom Karl and Jenny Marx would later often come to rely for loans while they were exiled in London.