First, he noted that all of the arguments for why archaeology benefited society were based in theory, and that archaeologists wanting to defend their discipline from its critics would therefore require a grounding in theory.[8] Second, he highlighted that theory was required to compare two different interpretations of the past and decide which one was the more likely.[9] Third, he asserted that theory was needed for the archaeologist to accept and admit to their own personal biases and agendas in interpreting the material evidence.[10] Finally, Johnson put forward what he considered to be the most important reason for the necessity of understanding theory; that all archaeologists, as human beings, are innately theoretical, in that they naturally make use of "theories, concepts, ideas, assumptions" in their work.