“Economic theory, since the time of the Physiocrats, has endeavored to get rid of the human will and to explain economic phenomena in terms of physical and hedonic forces. The human will had been the main reliance of the Mercantilists and of the economic theory of the Church fathers. But the will was arbitrary, capricious and contrary to natural laws. There were two stages of these physical theories which attempted to get away from the will:-the natural rights arld physical equilibrium stage of foreordained evolution of Quesnay, Adam Smith and Karl Marx, and the natural selection stage of blind evolution that followed Darwin, whose distinguished exponent in economics is Veblen. The theorists of each stage attempted to get rid of the human will and to explain economic phenomena as the working out of natural forces, either foreordained or blind. It was a concept of society as the natural growth of a mechanistic equilibrium.”

Notice sur les Titres et Travaux scientifiques de Pierre Duhem rédigée par lui-même lors de sa candidature à l'Académie des sciences (mai 1913), The Aim and Structure of Physical Theory (1906)

The Evolution of the Physicist's Picture of Nature (1963)
Context: It seems to be one of the fundamental features of nature that fundamental physical laws are described in terms of a mathematical theory of great beauty and power, needing quite a high standard of mathematics for one to understand it. You may wonder: Why is nature constructed along these lines? One can only answer that our present knowledge seems to show that nature is so constructed. We simply have to accept it. One could perhaps describe the situation by saying that God is a mathematician of a very high order, and He used very advanced mathematics in constructing the universe. Our feeble attempts at mathematics enable us to understand a bit of the universe, and as we proceed to develop higher and higher mathematics we can hope to understand the universe better.

Source: The Corporate Revolution in America, 1957, p. 287

From the Author's Preface to Third Edition (1919)
Space—Time—Matter (1952)

The Alchemy of Finance: Reading the Mind of the Market (1987)
Context: Economic theory is devoted to the study of equilibrium positions. The concept of equilibrium is very useful. It allows us to focus on the final outcome rather than the process that leads up to it. But the concept is also very deceptive. It has the aura of something empirical: since the adjustment process is supposed to lead to an equilibrium, an equilibrium position seems somehow implicit in our observations. That is not true. Equilibrium itself has rarely been observed in real life — market prices have a notorious habit of fluctuating.

Mind and Matter (1958)
Context: To my view the ‘statistical theory of time’ has an even stronger bearing on the philosophy of time than the theory of relativity. The latter, however revolutionary, leaves untouched the undirectional flow of time, which it presupposes, while the statistical theory constructs it from the order of events. This means a liberation from the tyranny of old Chronos. What we in our minds construct ourselves cannot, so I feel, have dictatorial power over our mind, neither the power of bringing it to the fore nor the power of annihilating it. But some of you, I am sure, will call this mysticism. So with all due acknowledgement to the fact that physical theory is at all times relative, in that it depends on certain basic assumptions, we may, or so I believe, assert that physical theory in its present stage strongly suggests the indestructibility of Mind by Time.

After all control and institutions and processes are immediate things. They can all be translated into terms of human conduct...
Source: The Institutional Approach to Economic Theory, 1919, p. 311-6

Source: The Turning Point (1982), p. 93.

Introduction to Capital. Introduction to volume 1 (1976)