Complex sentence: James had previously written one piece per month on television for "The Listener"-its editor, Karl Miller, had been an important influence on James and had allowed him to;' write a column which eschewed solemnity so thoroughly that it courted the frivolous.
Split into simpler sentences: James had previously written one piece per month on television for "The Listener" and its editor, Karl Miller, had been an important influence on James. He had allowed him to,' write a column which eschewed solemnity so thoroughly that it courted the frivolous.