Controlled Substance

Famous quotes containing the words controlled and/or substance:

“Science is a system of statements based on direct experience, and controlled by experimental verification. Verification in science is not, however, of single statements but of the entire system or a sub-system of such statements.”
—Rudolf Carnap (1891–1970)

“We are nothing but ceremony; ceremony carries us away, and we leave the substance of things; we hang on to the branches and abandon the trunk and body.”
—Michel de Montaigne (1533–1592)