The origins of modern northern European thought is a German aesthetic philosophy of the 1890s. By the 1920s, Einstein's theories of relativity were replacing Newton's conception of universal space. Practitioners such as Fletcher Steele, James Rose, Garrett Eckbo, and Dan Kiley began to write and design through a vocabulary of lines, volumes, masses and planes in an attempt to replace the prevalent debate, centered around ideas of the formal and informal, with one that would more closely align their field with the fine arts.