“The problem with Christian culture is we think of love as a commodity. We use it like money.”

Vol. I, Ch. 3, Section 2, pg. 121.
Das Kapital (Buch I) (1867)

Source: A Sand County Almanac, 1949, Foreword, p. viii.
Context: Conservation is getting nowhere because it is incompatible with our Abrahamic concept of land. We abuse land because we regard it as a commodity belonging to us. When we see land as a community to which we belong, we may begin to use it with love and respect. There is no other way for land to survive the impact of mechanized man, nor for us to reap from it the aesthetic harvest it is capable, under science, of contributing to culture.

"Beat Establishment: City Lights Bookstore May Be Named San Francisco Landmark", http://transcripts.cnn.com/TRANSCRIPTS/0006/25/sun.03.html CNN, 2000-06-25. : On book categories in City Lights bookshop.
2000s

Source: The World We Want (2000), Chapter 1, The World We Have, p. 3.

Source: A Sand County Almanac, 1949, Foreword, p. viii.

"Einstein's famous saying in Copenhagen", as quoted in a FBIS Daily Report https://books.google.de/books?id=DfQTAQAAMAAJ&q=%22We+cannot+solve%22: East Europe (4 April 1995), p. 45
Disputed

The Divine Commodity: Discovering A Faith Beyond Consumer Christianity (2009, Zondervan)

Cults, Sects and Questions (c. 1979)

Source: The Perks of Being a Wallflower