The main thesis of Max Weber's book is the definite link between the Protestant Ethic and the Spirit of Capitalism: `through which fruits can the Reformed see without doubt that he has the right faith: when his Christian life increases God's glory. Only a chosen one has really the Fidex efficax; only he is capable of being reborn and from this sanctification can he during his whole life increase God's glory with good works. So, good works are in no way means of obtaining salvation, but only a sign that one has been elected.' (Adaptation of the German text. LR)
The relationship between `God's glory' and `good works', is expressed by a rationalization of man's economic life (work).
This thesis is, in fact, a response to Marx's theory, which states that ideas, beliefs, ideologies are part only of the superstructure. The real foundations are the property and production relations between the classes, with on the one hand, the owners of the means of production (the capitalists) and on the other hand, the owners of the labor force, which they are forced to sell to the capitalists (the proletarians).
By demonstrating that religious 'ideas' also influence the socio-economic behavior of man, Max Weber wanted to prove that the base structure also includes ideas.
Money in circulation and capitalism
But there is a whole other aspect of the influence Protestantism, a very palpable one and not in the minds of people.
For a long period of time, 75% of all the money in circulation in Europe was in the hands of the Catholic Church (W. Manchester). What did the Church with this money? She built many Versailles (churches); in other words a sort of Western potlatch.
The radical change came, on the continent, with Protestantism and in England, with Henry VIII (G. M. Trevelyan). From then on, entrepreneurs and merchants could keep a big part of their money, which before had been confiscated by the Church. They invested it in new profitable businesses.
A simple example as illustration: when in the 16th century, Antwerp was besieged by the Catholic Spanish King, Philip II, all `Protestant' entrepreneurs and merchants fled the city and settled in Amsterdam. They created there a golden age (the beginning of pure capitalism for I. Wallerstein).
Max Weber's book is a must read for all those interested in Western history.