 The Curtisses wrote several books during World War I, including The War Crisis (1914) or The Philosophy of War, being a philosophical treatise on the mystical causes of war, and The Key to the Universe (1915).In the latter volume they contended that all personal experiences are expressions of one great law based on mathematical principles and that the "unfoldment of the godlike possibilities inherent in each Soul follows, step by step, the same order of events that is followed in the evolution of the Cosmos, and that such steps are symbolized by the first 22 numbers".Realms of the Living Dead