1. An earlier version of this paper was given at The Arthur Prior Memorial Conference in Philosophy and Logic, held in Christchurch, New Zealand in 1989, preprinted in the Auckland Philosophy Papers series (1990.1) as "Aquinas, Ockham, and Prior (and the unexpected examination)." This version of the paper has benefitted from comments made during that session, and particularly from subsequent comments by Christopher Martin of the University of Auckland.
2. William Ockham, Tractatus de Praedestinatione et de Praescientia Dei Respectu Futurorum Contingentium (hereafter DP), in Opera Philosophica II, ed. Philotheus Boehner (New York: St. Bonaventure, 1978). The Tractatus de Praedestinatione has been translated with a commentary by Marily McCord Adams and Norman Kretzmann as William Ockham: Predestination, God's Foreknowledge, and Future Contingents (Indianapolis: Hackett Press, 2nd ed., 1983, hereafter AK). AK also includes three very useful appendices: Appendix I contains Distinctions 38 and 39 of Scriptum in Librum Primum Sententiarum (Ordinatio), Distinctiones XIX-XLVIII, ed. G. I. Etzkorn and F. E. Kelley, Opera Theologica IV, (New York: St. Bonaventure, 1979). Appendix II contains the commentary on ch. 9 of In Perihermenias: Expositio in Librum Perihermenias Aristotelis, in Opera Philosophica II, ed. A. Gambatese and S. Brown (New York: St. Bonaventure, 1978). Appendix III contains most of ch. 32 of Summa Logicae III.3, in Opera Philosophica I, ed. P. Boehner, G. Gál, S. Brown (New York: St. Bonaventure, 1974). See also A. N. Prior, Past Present and Future (Oxford: Clarendon Press, 1967) and, for development and discussion of Prior's Ockhamist system, R. Thomason, "Combinations of Tense and Modality," in D. Gabbay and D. Guenthner, eds., Handbook of Philosophical Logic, II (Dordrecht: D. Reidel), 135-165.
3. For a discussion of the background to Ockham on future contingents see Calvin Normore, The Logic of Time and Modality in the Later Middle Ages: The Contribution of William of Ockham (diss., U. of Toronto, 1975, National Library of Canada No. TC35093), and "Future Contingents," in N. Kretzmann, A. Kenny, and J. Pinborg, eds., The Cambridge History of Later Medieval Philosophy (Cambridge: Cambridge University Press, 1987); and M. McCord Adams, William Ockham 2 vols. (Notre Dame: University of Notre Dame Press, 1987), especially chs. 20, 27, and 31. For the relation between Ockham and Scotus see, in addition to Adams, Martin Tweedale's complementary "Critical Notice of William Ockham," Canadian Journal of Philosophy 21 (1991): 211-244.
4. "Before the cock crow twice, thou shalt deny me thrice" (Mark 14.30) provides a case of such knowledge in the past, while the stock example of a revealed future contingent was "Antichrist will come" (1 John 2.18; 4.3). Having a named future entity was useful to logicians: see, e.g., William of Sherwood, Treatise on Syncategorematic Words, trans. Norman Kretzmann (University of Minnesota Press, 1968), 15.1, 17.7; William Ockham, In Perihermenias, 2.4.9 (O Ph 2:456), and Buridan, Sophisms on Meaning and Truth, trans. Theodore Kermit Scott (New York: Appleton Century Crofts, 1966), 5.3 and 7.5. Only God could have unrevealed knowledge of contingent truths about future individuals. Such knowledge of things 'in themselves' was not available to created intellects, including the angels. However truths about actually designated future individuals could be revealed, and Antichrist provided a striking example. See St. Thomas Aquinas, Summa Theologiae (hereafter ST), 1a 57.3.
5. ST 3a 75.7 ad 1. Scotus introduces the notion of "instants of nature" in this connection, but they have more to do with logical dependence than with chronological simultaneity. See Ordinatio I, Dist. 38, in Opera Omnia, ed. P. Carolo Balić [Vatican: Typis Polyglottis Vaticanis, 1950], 4:418ff; Adams, William Ockham, 2:1131; Tweedale, "Critical Notice," 237. For Ockham's acceptance of Thomas's position see Summa Logicae, III.3, ch 32, O Ph 1:713-14, AK 114.