- 1. See Descartes (1986 [1637, 1641, 1644]); Davidson (1980).
- 2. We follow here F. Giunchiglia's distinction between 'situation', as a way to record 'the state of the world as it is, independently of how it is represented in the mind of the reasoner' (Giunchiglia, 1993, p. 146), and 'context' as 'a theory of the world which encodes an individual's subjective perspective about it' (Giunchiglia, 1993, p. 145).
- 3. According to Maria Carla Galavotti, Keynes's attitude may be explained in terms of his adherence to 'a moderate form of logicism, quite different from the strictly formal approach later developed by Carnap. Keynes' logicism is pervaded by a deeply felt need not to lose sight of ordinary speech and practice, and assigns an important role to intuition and individual judgement' (Galavotti, 2005, p. 147).
- 4. As noted by Anthony W. F. Edwards, 'the quantification of surprise in terms of probability is likely to tell only half the story' (Edwards, 1992, p. 203). Keynes's weight of argument gives a cue into reasons for disbelief and possible causes of transition from belief to disbelief (or vice versa) as context is changed.
- 5. We are grateful to Domenico Costantini for calling our attention to this passage of the Treatise on Probability.
- 6. This entails identifying which problems can be addressed and the type of tools that may be used to that purpose. In that connection, Isaac Levi points out that 'we cannot be obliged to recognize all the logical consequences of our full beliefs or even enough of the consequences to solve some particular complicated problem' (Levi, 1997, p. 9).
- 7. The relationship between language, descriptions and permissible events is also considered in Crisma (1988).
- 8. The concept of 'prototypical form', in its association with the analysis of granular information, had been anticipated in Adam Smith's Theory of Moral Sentiments (Smith, 1976 ). See for example, the following passage: '[T]he beauty of each species, though in one sense the rarest of all things, because few individuals hit this middle form exactly, yet in another, is the most common, because all the deviations from it resemble it more than they resemble one another' (Smith, 1976 , pp. 198-9).
- 9. This point of view is rooted in the distinction between the way in which events (or situations) are described and the way in which knowledge about those events (situations) may be achieved. As Keynes noted, ''[I]f different wholes were subject to different laws qua wholes and not simply on account of and in proportion to the differences of their parts, knowledge of a part could not lead, it would seem, even to presumptive or probable knowledge as to its association with other parts. Given, on the other hand, a number of [...] atomic units and the laws connecting them, it would be possible to deduce their effects pro tanto without an exhaustive knowledge of all the coexisting circumstances' (Keynes, 1973 , pp. 277-8). Alberto Pasquinelli and Silva Marzetti Dall'Aste Brandolini argue that the above methodological standpoint may be at the root of Keynes's apparent switch to an 'organic' point of view in the General Theory (Pasquinelli and Marzetti Dall'Aste Brandolini, 1994, p. xviii).