Step 1: Understanding the Concept:
This question requires identifying the author of a specific quote that describes the central role of money in the study of economics.
Step 2: Detailed Explanation:
\begin{itemize}
\item The statement was made by Alfred Marshall, a highly influential neoclassical economist.
\item In his seminal work, "Principles of Economics" (1890), Marshall defined economics as "a study of mankind in the ordinary business of life." He further explained that while economics examines welfare, it is primarily concerned with those aspects of welfare that can be brought "directly or indirectly into relation with the measuring-rod of money."
\item For Marshall, money was not the end goal of economic activity, but it was the essential tool—the "pivot"—that allowed economists to measure and compare the strengths of human desires, motives, and satisfactions in a practical and quantitative way.
\end{itemize}
Step 3: Final Answer:
The statement is attributed to Alfred Marshall.