1. R. Adamson, On the Philosophy of Kant (Edinburgh: David Douglas, 1879), p. 150.
2. J. T. Merz, A History of European Thought in the Nineteenth Century (Edinburgh and London: Wm. Blackwood & Sons Ltd., 1903), vol. ii, p. 286.
3. B. Bosanquet, Logic or the Morphology of Knowledge (Oxford Press, 1911), vol. i, p. 30. The cyclical procedure applied to a single subject, e.g., history, is known as the concentric method. See
4. H. M. Knox, Introduction to Educational Method (London: Oldbourne, 1911), pp. 111–17.