Influential historian of ideas. Lovejoy was born in Berlin, but after studying in California was hired at Stanford and then in 1910 by Johns Hopkins, where he stayed for the rest of his working life. His method was premised on the concept of a ‘unit-idea’: a building block of thought traceable across time, assemblages of which make up different philosophies and ideologies. His most famous work was The Great Chain of Being (1936). See also chain of being; plenitude, principle of.