1.  What is the spirit of capitalism?

Weber sums up spirit of capitalism through Ben Franklin's phrase "time is money."  Weber uses Franklin's peculiar "inside-out" autobiography to stand for the modern understanding of capitalism.  In Franklin's moral economy, all action (whether private or public) should be "read" as demonstration of public morality. One's personal and public reputation is most efficacious (and most virtuous) when it is the surety for the borrowing money.  Weber argues that the spirit of modern capitalism is not merely "astuteness" in business -- a quality which can be found in any age or culture -- but rather "the idea of a duty of the individual toward the increase of his capital, which is assumed as an end in itself." (51) It is an ascetic, not hedonistic, impulse. This ethic is particular to the West, particular to the modern era.

N.B. Although it would be possible to argue that Franklin's beliefs and practices were, if anything, at the very tail end of wherever Calvinism might lead, there is a characteristic feature of the writing that makes Franklin's autobiography richly suggestive to anyone thinking about money and God.  Weber mentions that Franklin tracks his efforts to practice morality through a weekly chart and alludes to Franklin's practice of peppering his conversation with humility hedges such as "it seems to me,"  or "it appears that..."  With regard to his chart, Franklin says that a Quaker friend pointed out that he had forgotten to include "humility" in his list of virtues.  Franklin concluded that, for himself, humility was impossible to acquire in truth, but the appearance served just as well.  For Franklin, awareness of the distance between appearance and reality is habitually collapsed by emphasizing, and so "flattening" -- ironic moments in the autobiography -- and not only "flattening" them but also displaying them as opportunities for making money (as above) or moralizing.
(see p. 53 for Prov. 22:29)

2.  What is the spirit of Protestantism? Why is Calvinism best suited to support capitalism?

Luther's crucial insight and bedrock theological position is sola fide, salvation through faith alone (Ephesians 2:8-9). Weber is interested in the practical workings out of that belief:  life as a "calling." "The only  way of living acceptably to God was not to surpass worldly morality in monastic asceticism, but solely through the fulfilment (sic) of the obligations imposed upon the individual by his position in the world.  That was his calling." (80)  In fact, the concept of the "calling" is as crucial to Weber as sola fide is to Luther.

Calvinism builds upon sola fide the security and terror of predestination and election.  Calvin suggest that believers ought each to be a singularity before God ("unprecedented inner loneliness...forced to follow his path alone to meet a destiny which had been decreed for him from eternity" 104) set into a tight earthly organization of the heaven-bound.  The emotional surety of salvation is a breakthrough moment -- and from then on, the believer has an obligation to express his or her self-confidence in salvation through the dedication of every moment, pleasure, thought and action God's glory.  "The elected Christian is in the world only to increase this glory of God by fulfilling his commandments to the best of his ability." (108)  Such works will be obviously blessed by Him.  In this understanding of "calling," Job serves as an exemplar. When God's hand of protection was removed, Job lost flocks, children, and health.  Tempted by Satan and his wife to "curse God and die," Job resisted, proclaimed his own righteousness in the face of his "comforters" and insisted that he wanted to know why God was persecuting him.  Having had his desired meeting with God, and having been completely humbled by the confrontation, Job declares "I have heard of thee by the hearing of the ear;  but now mine eye seeth thee. Wherefore I abhor myself, and repent in dust and ashes." (Job 42:5-6)  Then he is blessed with twice as many worldly possessions as he had lost.

Weber sees in the Calvinistic version of morality the death of magic and the birth of rationalized business systems.  He argues that "the God of Calvinism demanded of his believers not single good works, but a life of good works combined into a unified system." (117)

4.  How does Protestant asceticism support capitalism?

Weber argues that a group of men armed with Calvinist beliefs would be unstoppable in business.  For one, they wouldn't believe in taking rests.  And also, they would believe that business ought to be pursued as rationally and impartially as Franklin practiced morality.  Weber contrasts medieval and Renaissance attitudes towards business.  Both versions of "...asceticism  looked upon the pursuit of wealth as an end in itself as  highly reprehensible; but the attainment of it as a fruit of labor in a calling was a sign of God's blessing.  And even more important: the religious valuation of restless, continuous, systematic work in a worldly calling, as the highest means to asceticism, and at the same time the surest and most evident proof of rebirth and genuine faith, must have been the most powerful conceivable lever for the expansion of that attitude toward life which we have here called the spirit of capitalism." (172)

5.  Why did Weber write this essay?  To what scholarly tradition was he contributing?

Weber argues that capitalists -- in the Braudellian sense -- have existed as long as trade and financial instruments/organizations supporting the risk involved in trade have existed. Weber wants (p. 21) to explain the peculiar Western "rational capitalistic organization of (formally) free labor" and the concomitant form of citizenship expressed through free labor under regular (mental) discipline.