  On the other hand, analysis was seen more positively, but the Kantian conception underwent a certain degree of modification and  development. In the nineteenth century, this was exemplified, in  particular, by Bolzano and the neo-Kantians. Bolzano's most  important innovation was the method of variation, which involves  considering what happens to the truth-value of a sentence when a  constituent term is substituted by another. This formed the basis for his reconstruction of the analytic/synthetic distinction,  Kant's account of which he found defective. The neo-Kantians  emphasized the role of structure in conceptualized experience and had a greater appreciation of forms of analysis in mathematics and  science. In many ways, their work attempts to do justice to  philosophical and scientific practice while recognizing the central  idealist claim that analysis is a kind of abstraction that inevitably involves falsification or distortion. On the neo-Kantian view, the  complexity of experience is a complexity of form and content rather  than of separable constituents, requiring analysis into  ‘moments’ or ‘aspects’ rather than  ‘elements’ or ‘parts’. In the 1910s, the idea was articulated with great subtlety by Ernst Cassirer   [Quotation],  and became familiar in Gestalt psychology.