Final answer:
True, Max Weber argued that Calvinists looked for signs of salvation in their success and prosperity, which aligned with the Protestant work ethic and the development of capitalism.
Step-by-step explanation:
According to Max Weber, the "sign" Calvinists looked for as an indication they were saved was indeed their successful investment in capital. This is grounded in the Calvinist principle of predestination, which suggests that one's eternal fate is predetermined. Calvinists, therefore, viewed success in their worldly endeavors, such as hard work and prosperity, as signs of being among the elect, or those predestined for salvation. The Protestant work ethic, as proposed by Weber, thus played a crucial role in the development of capitalism, with Protestant values emphasizing hard work, frugality, and success as indicators of divine favor.