The energy of good (love, mercy, chastity, innocence, prayer, morality, etc.) in a society moves from a potential state to the threshold of its actuality on a scale of measurable variation. When such a 'movement' from bottom to top reaches a certain level of intensity, the measurable effect is the emergence of a dense spiritual space.Its scaling is measurable through specified effects such as the decrease in the number of crimes, acts of injustice, unfairness, social and political propensity to wars, anarchy etc.Weber explained the emergence of the modern capitalist order by such a dense spiritual space confirmed by the new (ascetic) vitalismas its measurable item (he correlated technological inventiveness in the European space with protestant ethics and concluded thatthe rising of anew order is endowed to this new spiritual vitalism, which induced an unmistakable noologic density). Durkheim underlined the efficiency of the religious factor, highlighted by the belonging to the three Christian confessions, as a factor of protection of the European family against the risk of suicide. Therefore, in the world, there are dense spiritual spaces and diffluent spaces, with low spiritual density (low noologic power). Historical periods are differentiated themselves according to the same criterion, which enables us to delineate cultural epochs. The period at the end of the 19th century and beginning of the 20th century is marked by a growth of the noologic density in Europe from the North towards South, a growth which is attested by the emergence of a new stylistic configuration entitled the "1900 style"or Secession. The present study insists on the theories which compete to explain the emergence of spiritual dense spaces and revisits my own theory as it was used in my books, Noology (2000) and Noopolitics (2005), to explain the great crises of the European spirit during the two millennia after Christ.