No Principles of Economics?

The latest episode of Economic Update, Where Economic Theories Clash, strongly implies something I feared regarding the field of Economics. In it, Richard Wolff called Neo-classical economics, Keynesian economics and Marxian economics 'theories' of economics which implies they have undergone some form of validation or testing (scientific theories are vigorously tested before they are called 'theories'). But in real economies, each of these 'theories' has failed in one permutation or other. This suggests that Economics has no unifying principles. [To use the physical sciences as an example (again): the Theory of Evolution is a unifying principle in biology - it connects all living organisms and justifies the study of model organisms to better understand life; Atomic Theory is a unifying principle of chemistry - it predicts the behavior of all matter.] An example of a possible unifying economic principle is the presumption that functional economies must yield profit; this would have strong implications for capitalism.

This is particularly troubling when it comes to policy. All public policy is economic policy and it is argued and made on the basis of Economic theory. If Economic theory is as poorly developed as implied above, then for all intents and purposes, Economic theory is ideology without basis in empirical principle. As it stands now, the science of climate change has very strong physical evidence backing it and thus should drive energy policy. In its stead, we have nonsense 'economic' arguments that the cost of protecting the biosphere is 'too expensive'. Policy makers are balancing the future of humanity against the profiteering of capitalists at our ignorance. If science can detangle systems as complex as climate to predicted global climate change, it should be able to apply similar methods to answer the question of how to best structure economies for the sake of mankind. Economies should serve humanity not the other way around.