‘[T]he established critics of a theory have nearly as much interest in the survival of the theory they criticize as its supporters; for when it is abandoned they are transported from the exciting forefront of current scientific debate to a dignified but unexciting position in the museum of the history of the subject’ (Nuti [1974, p. 364]). ‘If anything explains the heat of debates in growth [and capital] theory, it is the difficulty thinkers in the scholastic tradition have in appreciating that, for workers in the scientific tradition, it makes sense to entertain a model and use it without being committed to it; while the scientists cannot imagine why mere models should be the object of passion’ (Mirrlees [1973, p. xxi]).