Marshall was born and educated in London, although he later lived outside the city. His approach sought to reconcile classical and modern thought.
Marshall was born in Charlotte Row, Bermondsey near to its unwholesome tannery area - the location, since redeveloped, was to the north side of Long Lane and east of Crosby Row. His family relocated for a time to the Bell Green area of Sydenham in southeast London before moving to the more prosperous area of Clapham. Though the house at 5 Russell Place, Larkhall Rise no longer exists the road is still there. He was schooled at Merchant Taylors School, then in Suffolk Lane in the City of London.