The aim of the paper is to reconstruct the historical development of classi
cal algebra from Al Khwarizmi to Lagrange and to analyse the fundamental ep
istemological shifts, which occurred in the understanding of basic algebrai
c concepts. The paper opens with a general characteristics of algebraic tho
ught as conceptualization of motor schemes. That puts algebra into a contra
st with geometry, which is based on conceptualization of the schemes of vis
ual perception. From contrasting these two ways of conceptualization, the m
otor and the visual, the author tries to explain why the ancient Greeks did
not develop algebraic thought. Further he uses his theory of evolution of
linguistic form to interpret the changes of the language of algebra beginni
ng with Al Khwarizmi's verbal rules, through Cardano's formulas, Cartesian
polynomial forms, up to Lagrange's theory of resolvents.