Published online by Cambridge University Press: 14 March 2022
The attribute of living is due either to a specific state of matter or to a distinctive kind of energy. All possible interpretations of these two concepts are materialistic with one exception. There is said to be a kind of energy apart from this world. Such an assumption is vitalistic.
1 I am indebted to a number of associates for information on several subjects here discussed, but to none so much as to Dr. John Northrop, to whom I express my gratitude for his helpful and delightfully stimulating letters dealing with the properties of proteins, enzymes, and viruses; but I relieve him of all responsibility for the deductions made from the information obtained.