This paper draws attention to four central concepts in Schrödinger's 'What is Life?' that have not, as yet, received sufficient attention in the domain of complexity: delayed entropy, free energy, order out of order and aperiodic crystal. It then demonstrates the important role the four elements play in the dynamics of complex systems by elaborating on their implications for cities as complex systems.
Keywords: delayed entropy; free energy; genetic code; order out of order and aperiodic crystal.