Thing Knowledge: A Philosophy of Scientific Instruments (University of California Press, 2004) challenges the traditional view that knowledge is primarily expressed in words, formulas, and propositions. Instead, the book argues that scientific instruments themselves embody knowledge—“thing knowledge.” These instruments aren’t just tools used to support theory; they are forms of scientific knowledge in their own right. The book uses a wide array of historical case studies—from 18th-century mechanical models to 20^th century cyclotrons and spectrometers—to show how instruments shaped science. Instrument development often drives science forward in ways that precede or outlast specific theories.