The Memorial Foundation for Jewish Culture supported the research on which this study is based; I am pleased here to thank the Foundation for its support. For their intellectual support, I am indebted to Gad Freudenthal, Bernard R. Goldstein, and Giora Hon.

1. It is difficult to write on this subject without falling into anachronistic usages.The closest medieval terms for what we mean by the modern expression “science” in the broad sense seem to be ḥokhmah(“wisdom”) or 'iyyun(“looking into,” “speculation”), both of which can be translated back into modern English more easily as “philosophy” than as “science.” Ḥokhmah,however, can also mean a specific discipline, and as such is adequately captured by the modern term “science” when it refers to a specific scientific discipline.But here, too, the overlap in meaning is hardly isomorphic.The main problem is that between the time of Maimonides and his contemporaries and our own day, the great scientific revolution of the sixteenth and seventeenth centuries took place and the term “science” began carrying with it a whole new range of sociological and epistemological meanings; furthermore, the term “scientist” was coined, a usage which has no place in discussions of medieval thought.Another notoriously problematic term is “progress,” and where I am forced to use it I hope that I can avoid invoking wholly inappropriate connotations.It is hard to avoid using the term, however, since Maimonides and some of his contemporaries held a “whiggish” view of the history of natural sciences, according to which they had indeed progressed beyond the accomplishments of their predecessors.On whig interpretations of history generally, see Herbert Butterfield, The Whig Interpretation of History(London: G.Bell & Sons, 1963); on whig interpretations of the history of science, see, for example, Stephen Jay Gould, Time's Arrow, Time's Cycle(Cambridge, Mass.: Harvard University Press, 1987), pp.4–5.

2. I discuss Maimonides' conception of intellectualauthority generally in “Reading Rambam: Approaches to the Interpretation of Maimonides,” Jewish History5 (1991): 73–93.Google Scholar

3. “On the Status of the Astronomy and Physics in Maimonides' Mishneh Torahand Guide of the Perplexed: A Chapter in the History of Science,” British Journal for the History of Science24 (1991): 453–63.Google Scholar

4. “Maimonides and Gersonides on Astronomy and Metaphysics,” in Kottek, S. and F. Rosner Maimonides on Medicine, Science and Philosophy, ed.Kottek, S and F. Rosner (New York: Jason Aronson, 1991 /1993).Google Scholar

5. Laws of the Foundation of the Torah 1.1.This translation is my own.Subsequent translations from Laws of the Foundations of the Torah will be from Moses Hyamson, ed.and trans., Maimonides, The Book of Knowledge(Jerusalem: Feldheim, 1974).Isaac Abravanel suggested that Maimonides meant to say here that the basic dogma of religious belief is the basic axiom of all the sciences; i.e., that religious belief and science share the same starting point and hence must arrive at the same conclusions.Abravanel makes this claim in his Rosh Amanah,chap.5.In my translation, Principles of Faith(East Brunswick, N.J.: Associated University Presses for the Littman Library of Jewish Civilization, 1982), p.76.For an argument to the effect that Abravanel was correct in his assessment of Maimonides here, see my Maimonides on Judaism and the Jewish People(Albany: SUNY Press, 1991).Google Scholar

6. Foundations 1.6.In his book enumerating the commandments, Sefer ha-Mizvot,this is positive commandment no.1.

7. The obligation to study God's works in order to know God to some extent is one of the recurring motifs of medieval Jewish philosophical thought.See, for example, Harvey, Steven, Falaquera's “Epistle of the Debate” (Cambridge, Mass.: Harvard University Press, 1987), p.88.Google Scholar

8. For the identification of Separate Intellects, with angels, see Maimonides' Guide of the Perplexed,pt.2, chap.6.In the translation of Shlomo Pines (Chicago: University of Chicago Press, 1963), p.262.Subsequent citations from the Guidewill be from this translation.The question of the relationship between the views Maimonides expresses in the Mishneh Torahand those which he expresses in the Guide of the Perplexed(and the exact nature of the views which he espouses in the Guide)is one of the most hotly debated issues in current Maimonidean scholarship.Recent studies which focus on this issue include Oliver Leaman, Moses Maimonides(London: Routledge, 1989); Marvin Fox, Interpreting Maimonides(Chicago: University of Chicago Press, 1990); and Menachem Kellner, Maimonides on Judaism and the Jewish People(Albany: SUNY Press, 1991).The nature of science is not an issue which Maimonides addressed directly (exoterically or esoterically) and is not a question on which he can reasonably be thought to have had an esoteric teaching.Google Scholar

9. Maimonides says that these chapters deal with Ma'aseh Merkavah(“Account of [Ezekiel's vision of] the Chariot”) in Foundations 2.11.For the claim that Ma'aseh Merkavahmeans metaphysics, see Maimonides' commentary on Mishnah Hagigah2.1, Guide1, Introduction (p.6), and my detailed discussion in Maimonides on Judaism and the Jewish People,chap.8.

10. Maimonides says that these chapters deal with Ma'aseh Bereshit(“Account of Creation”) in Foundations 4.10.For the claim that Ma'aseh Bereshitmeans physics, see Maimonides' commentary on Mishnah Hagigah2.1, Guide1, Introduction (p.6), and my detailed discussion in Maimonides on Judaism and the Jewish People,chap.8.

11. For a detailed and nuanced discussion of Maimonides' statements on this matter, see Twersky, Isadore, Introduction to the Code of Maimonides (Mishneh Torah) (New Haven: Yale University Press, 1980), pp.97–187.Google Scholar

12. As Maimonides states: “On these grounds I, Moses, the son of Maimon, the Sefardi, bestirred myself, and, relying on the help of God, Blessed be He, intently studied all these works, with the view of putting together the results obtained from them in regard to what is forbidden or permitted, clean or unclean, and the other rules of the Torah–all in plain language and terse style, so that thus the entire Oral Law might become systematically known to all…[and so] that all the rules shall be acessible to young and old…so that no other work should be needed for ascertaining any of the laws of Israel, but that this work might serve as a compendium of the entire Oral Law….Hence, I have entitled this work Mishneh Torah(Repetition of the Law), for the reason that a person who first reads the Written Law and then this compilation, will know from it the whole of the Oral Law, without having occasion to consult any other book between them” (Mishneh Torah,Introduction, Hyamson, p.4b).See further Kasher, Hannah, “The Study of Torah as a Means of Apprehending God in Maimonides' Thought,” Jerusalem Studies in Jewish Thought 5 (1986): 71–81 (Hebrew).Google Scholar

13. Not every traditionalist interpreter of Maimonides takes this view.R.Meir Leibush Malbim, the nineteenth-century author of a popular and highly traditionalist commentary on the Bible, in his Commentary to Ezekiel(Vilna, 1911), p.3a, rejects Maimonides' explanation of Ezekiel's Vision of the Chariot (Ma'aseh Merkavah)on the explicit grounds that “the foundations on which he built it have been refuted.The astronomy, natural science, and ancient philosophy which were the foundations and supports of his interpretation have been completely undermined and destroyed by the scientific research which has developed in recent generations.” I cite this passage as it is brought by Marvin Fox, Interpreting Maimonides,pp.23–24.Google Scholar

14. But not necessarily; seeHeschel, Abraham Joshua, “Did Maimonides Believe That He Had Attained Prophecy?” Louis Ginzberg Jubilee Volume (New York: American Academy for Jewish Research, 1946), pp.159–188.Google Scholar

15. The issue gains further importance in the light of a comment by Isadore Twersky to the effect that for Maimonides, “knowledge of the physical sciences is necessary for a correct understanding of halakhah.” SeeTwersky, , “Halakhah and Science: Perspectives on the Epistemology of Maimonides,” Hebrew Law Annual 14–15 (1988–1989): 121–151 (Hebrew), p.132.I am not competent to go into the question of the status of specific halakhic decisions (if any) in the Mishneh Torahwhich depend upon now rejected theories concerning the nature of the physical world.But if Twersky is correct in his assessment (and the evidence he adduces is most convincing), then the question of Maimonides' own understanding of the status of the physics and biology he presents in the Mishneh Torahshould be of crucial interest and importance to historians of halakhah.Google Scholar Further on the issue of halakhah and science, see the remarks of Rosenberg, Shalom, Torah u-Madda' bi-Hagut ha-Yehudit ha-Hadashah (Jerusalem: Ministry of Education and Culture, 1988), pp.58–62.Google Scholar

16. Although I did my best to ignore it in an earlier draft of this essay; my thanks to Gad Freudenthal for not allowing me to get away with it.

17. On this, see my Dogma in Medieval Jewish Thought(Oxford: Oxford University Press, 1986), chap.1.Google Scholar

18. See my “Astronomy and Physics in Maimonides' Mishneh Torahand Guide of the Perplexed.”I there argue that even though Maimonides clearly held what would today be called a “whiggish” view of scientific progress, and also held that the sciences could reach perfection or completion, he still maintained that the science in the Mishneh Torahwas simply the most up-to-date scientific information available to him, not the most perfect account of science which could ever be reached.In proving this I noted that Maimonides distinguished radically between sublunar and superlunar science: the former could reach completion, and in fact had been brought to completion; the latter was incomplete and would forever remain so.It must remain incomplete and unperfected because the heavens are the heavens of the Lordand will always remain beyond our ken, both in terms of the actual motions of the heavenly bodies and in terms of what we can know about the incorporeal intellects associated with those bodies.In other words, the actual truth concerning celestial physics and concerning metaphysics lies beyond the limits of human knowledge.This position (which aids him in the solution of many theological problems) forces Maimonides to adopt an instrumentalist view of astronomy, according to which it is the goal of the astronomer to provide a mathematical model of the observed motions of the heavenly bodies (to “save the phenomena”), not to describe them as they actually are.Maimonides' instrumentalism, then, is a handmaiden of his theology.Admitting that metaphysics and celestial physics will never be brought to completion, perhaps in Maimonides' day they had reached the highest level they ever would reach? Were that the case, then perhaps the account of natural matters given in the Mishneh Torahreally does represent the most complete possible picture and not simply the most up-to-date picture available to Maimonides.Two reasons were adduced for rejecting this hypothesis: first, Maimonides himself foresaw the possibility of progress in the understanding of superlunar phenomena; second; the account of astronomical matters presented in the Mishneh Torahis simply incorrect on Maimonides' own terms as expressed in the Guide of the Perplexedand thus could not represent his view of the most perfect possible view of superlunar science.

19. Laws of Kings and Their Wars 12.2.1 cite the translation of Hershman, A.M., Book of Judges (New Haven: Yale University Press, 1949).Google Scholar For Maimonides' attitude toward midrash in general, see the introduction to his commentary on Mishnah Sanhedrin, Perek Helek.The text is available in English in I.Twersky, ed., A Maimonides Reader(New York: Behrman House, 1972), pp.401–423.Compare furtherFox, Marvin, “Nahmanides on the Status of Aggadot: Perspectives on the Disputation at Barcelona, 1263,” Journal of Jewish Studies 40 (1989): 95–109.CrossRefGoogle Scholar

20. It might be objected to the argument being developed here that showing that Maimonides held that some of the sages could and did err proves nothing about his understanding of the epistemological status of his own science, since he may have held himself to be superior (in having reached a higher degree of intellectual perfection) to all or most of the sages.This is not the place to go into a detailed refutation of this hypothesis.Here it should suffice to note that this objection rests upon the claim that Maimonides presented as what Pines called “a convenient fiction” his argument that the prophets and sages had access to a philosophic tradition some of the elements of which he had succeeded in teasing out of the sources with enormous difficulty.This objection further rests on a reading of Maimonides which renders absurd his attempts to understand rabbinic allegories philosophically: if he held himself to be a better philosopher than all or most of the sages, why bother reconstructing the philosophic meaning under their allegories? I reject this approach to reading Maimonides.This rejection finds detailed expression in two recent books of mine, Maimonides on Human Perfection(Atlanta: Scholars Press, 1990) and Maimonides on Judaism and the Jewish People(Albany: SUNY Press, 1991).In the latter, for example, I show that Maimonides adopted unusual positions on religiousmatters (providence, prophecy, immortality, messianism, the nature of the Jewish people, the nature of the Torah, and others) because of his antecedent adoption of an Aristotelian psychology.Were his philosophic and religious concerns as radically divorced as Pines maintains, he could have saved himself from much aggravation and calumny by simply adopting unexceptionable, standard positions on these religious matters, even though such positions contradicted his “truly held” philosophical beliefs.For other recent studies critical of the Pines approach, see the books by Leaman and Fox, cited in n.8 above.

21. Pines cites Pesahim94b.

22. Pines cites On the Heavensii.9.290b.12 ff.

23. Pines cites Pesahim94b.

24. And, as Maimonides says, “For only truth pleases Him, may He be exalted, and only that which is false angers Him” (2.48, p.409).

25. Pirkei Mosheh,chap.25.1 quote from the translation ofSarton, George in “Maimonides: Philosopher and Physician,” Bulletin of the Cleveland Medical Library 2(1955): 3–22;Google Scholar reprinted inSarton on the History of Science, ed.Stimson, Dorothy (Cambridge, Mass.: Harvard University Press, 1962), pp.78–101.The passage quoted appears on p.89 of the reprint.In Fred Rosner's translation (The Medical Aphorisms of Maimonides,vol.2, trans, and ed.Fred Rosner and Suessman Muntner [New York: Yeshiva University Press, 1971]), the passage appears on pp.218–219.The Arabic original of Maimonides' Medical Aphorisms,known in Hebrew as Pirkei Mosheh,has never been published in its entirety.Portions of the Arabic text of the twenty-fifth chapter, with modern Hebrew translation, appear in Y.Kafih, ed.and trans., Iggerot ha-Rambam(Jerusalem: Mossad ha-Rav Kook, 1972), pp.148–167.Two medieval Hebrew translations were edited by Suessmann Muntner in Moshe ben Maimon (Maimonides) Medical Works,vol.2: Medical Aphorisms of Moses(Jerusalem: Mossad ha-Rav Kook, 1959).Google Scholar

26. Letter on Astrology, translated byLerner, Ralph in Medieval Political Philosophy, ed Lerner, Ralph and Mahdi, Muhsin (Ithaca: Cornell University Press, 1972), p.229.On this text, see Jacob I.Dienstag, “Maimonides' Letter on Astrology to the Rabbis of Southern France,” Kiryat Sefer61 (1987): 147–158 (Hebrew).Google Scholar

27. I.e., Maimonides had just proven that the rejection of astrology is “one of the roots of the religion of Moses our Master” (p.234).

28. Letter on Astrology, p.235.

29. Compare the passage cited above in n.19 from Laws of Kings 12.2.

30. This attitude of Maimonides' toward the sages finds indirect expression in another source.In Guide2.9 (p.268) Maimonides records the claim that there are nine spheres.But spheres can be counted in different ways (compare Laws of the Foundations of the Torah 3.2), and what one person counts as nine, another could count differently.“For this reason,” Maimonides says, “you should not regard as blameworthy” a rabbinic dictum which seems to indicate that there are only two spheres.Relevant to our theme here is the unarticulated supposition that in astronomical matters rabbinic dicta have to be brought into line with those of the astronomers, not the other way around.It was the rabbinic dictum which might be thought to be “blameworthy,” not that of the astronomers.Another indirect expression of Maimonides' idea that the sages could err on matters of physics and metaphysics may be found in his use of the expression “Ben Zoma is still outside” in Guide3.51 (p.619).As Marc Saperstein has shown in a remarkably sensitive reading of this passage in the Guide (Decoding the Rabbis[Cambridge, Mass.: Harvard University Press, 1980], p.18), Maimonides uses this text (from Hagigah15a) to indicate that Ben Zoma, a mishnaic sage, failed to attain mastery over the physical sciences and thus failed to attain even a rudimentary knowledge of God.Maimonides clearly felt that he himself was, and the student to whom he addressed the Guidecould be, superior to Ben Zoma in scientific (and hence religious) attainments.Ben Zoma, it should be recalled, was one of the three companions who sought to enter “Paradise” with R.Akiba (Hagigah14b).Ben Zoma apparently lost his mind as a result of this experience, adding to the impression that he would not have been considered by Maimonides to be one of the leading sages.On the Hagigahtext, see the discussion inScholem, Gershom, Jewish Gnosticism, Merkabah Mysticism, and Talmudic Tradition (New York: Jewish Theological Seminary, 1965), pp.14–19.Google Scholar

31. SeeRegev, Shaul, “The Vision of the Nobles of Israel in the Jewish Philosophy of the Middle Ages,” Jerusalem Studies in Jewish Thought 4 (1984/1985): 281–302 (Hebrew).Google Scholar

32. The point of Maimonides' discussion in Guide1.4–5.

33. Two points should be noted here.First, this means that the “nobles of the children of Israel” were superior in their intellectual attainments to Aristotle, who, as we shall see below, never achieved even the lowest level of prophetic inspiration; despite this they erred on an important metaphysical (and thus scientific) matter.Second, if Isaac Abravanel, Shalom Rosenberg, and W.Z.Harvey are all correct, then Maimonides even imputed scientific error to Ezekiel, who achieved the fifth degree of prophecy.For details, seeHarvey, Warren Zev, “How to Begin to Study The Guide of the Perplexed, 1,” Da'at 21 (1988): 5–23, pp.21–23 (Hebrew).Google Scholar

34. Hebrew (the Arabic original of the letter is lost): da'ato.Another possible translation is “his knowledge.” On Maimonides' use of this term, seeBaneth, David, “Maimonides' Philosophical Terminology,” Tarbiz 6 (1935): 258–284 (Hebrew), p.260,Google Scholar and Blumenthal, David R., “Maimonides on Mind and Metaphoric Language,” in Approaches to Judaism in Medieval Times, ed.D.R., Blumenthal, vol.2 (Chico: Scholars Press, 1985), pp.123–132.Google Scholar

35. Compare Guide of the Perplexed2.32–48.

36. I quote from Iggerot ha-Rambam,ed.and trans.Ya'akov Shilat (Jerusalem: Ma'aliyot, 1988), vol.2, p.553.On this letter seeMarx, Alexander, “Texts By and About Maimonides,” Jewish Quarterly Review 25 (1934-1935): 374–381;Google ScholarIvry, Alfred, “Islamic and Greek Influences on Maimonides' Philosophy,” in Maimonides and Philosophy, ed.S., Pines and Y., Yovel (Dordrecht: Martinus Nijhoff, 1986), pp.139–156; and Shlomo Pines, “Translator's Introduction,” p.lix, in Pines's translation of the Guide.CrossRefGoogle Scholar

37. See also 2.23 (p.332).Jose Faur plays down the significance of these passages, interpreting them so as to diminish Maimonides' admiration for Aristotle.See his 'Iyyunim ba-Mishneh Torah li-ha-Rainbam,p.7.I find Faur's interpretation forced, an estimation reinforced by the fact that Shem Tov ibn Falaquera, Maimonides' great thirteenth-century admirer, criticized the Master for his excessive admiration of Aristotle.SeeMalter, Henry, “Shem Tob ben Jospeh Palquera II: His 'Treatise of the Dream',” Jewish Quarterly Review 1 (1910-1911): 451–501, p.492.CrossRefGoogle Scholar

38. P.230; I have slightly emended the translation.

39. This is the burden of Maimonides' refutation of Aristotle's thesis concerning the eternity of the world in Guide2.13–31; see especially chap.17.

40. Compare also 2.3, p.254.Here we have an example of Maimonides' whig interpretation of the history of science.

41. The argument here rests upon the assumption that Maimonides saw himself as part of an ongoing process of investigation into physics and metaphysics; if he thought that his own work (or generation) marked the capstone of all possible scientific development, then my argument clearly fails.That he did not so think is shown by the text I will cite immediately below from 2.24 (p.327).

42. I say “details of the account” because it is safe to say that Maimonides would be very surprised by Copernicus, Newton, and Einstein.Acceptance of some notion of development in the understanding of the universe in the Middle Ages cannot be equated with our modern expectation that just as the Newtonian universe was replaced by the Einsteinian, the Einsteinian universe may very well be replaced by another vision of the structure of the cosmos.

43. For details, seeMarx, Alexander, “Maimonides and the Scholars of Southern France,” Hebrew Union College Annual 3 (1926): 325–335;Google Scholar reprinted inMarx, , Studies in Jewish History and Booklore (New York: Jewish Theological Seminary, 1944), pp.48–62.The passage in question is found on p.52 of the reprint.Google Scholar

44. The Medical Aphorisms of Maimonides, vol.2, translated and edited by Rosner, Fred and Muntner, Suessman (New York: Yeshiva University, 1971), p.205.Google Scholar

45. Further on this point, see the discussion in my “Astronomy and Physics in Maimonides' Mishneh Torahand Guide of the Perplexed,”the conclusions of which are summarized above inn.18.

46. On worship in Maimonides as philosophical meditation, see Guide3.51;Fox, M., “Prayer in the Thought of Maimonides,” in Ha-Tefilah ha-Yehudit: Hemshekh vi-Hiddush, ed.G., Cohen (Ramat Gan: Bar Ilan University Press, 1978), pp.142–167 (Hebrew); and my Maimonides on Human Perfection,pp.31–33.Fox's article is now available in English in his Interpreting Maimonides,pp.297–321.Google Scholar

47. This last point was suggested to me byRoss, J.J..See “Maimonides and Progress–Maimonides' Concept of History,” in Hevrah vi-Historiah, ed.Cohen, Yehezkel (Jerusalem: Ministry of Education and Culture, 1980), pp.529–542 (Hebrew).Google Scholar

48. Laws of Kings 11.4.The text here is not without its problems, none of which, however, impinge upon our discussion.SeeBlidstein, Ya'akov, “On Universal Rule in Maimonides' Eschatological Vision,” in 'Arakhim bi-Mivhan ha-Milhamah (Alon Shevut: Yeshivat Har Ezion, n.d.), pp.155–172, n.54 (Hebrew).I cite the translation of A.M.Hershman, Book of Judges,p.240.Google Scholar

49. 11.4; presented by Hershman on pp.xxiii–xxiv.SeeHershman's comments there and Goldfeld, Leah Naomi, “Laws of Kings, Their Wars, and the King Messiah,” Sinai 91 (1983): 67–79 (Hebrew).Google Scholar

50. Lest it be objected that there is no necessary connection between spiritual and scientific improvement, let the following be noted: (a) true monotheism, for Maimonides, depends upon the correct intellectual apprehension of God; Maimonides' messianism, therefore, is based upon the assumption of universal intellectual(i.e., scientific) progress; (b) in general, and this is only to restate the previous point in broader terms, Maimonides did not view perfection as something which was radically divisible: true perfection in one area necessarily went hand in hand with true perfection in other areas; radical spiritual progress could not be absolutely divorced from radical intellectual (i.e., scientific) progress.

51. On this subject, seeRescher, Nicholas, The Limits of Science (Berkeley: University of California Press, 1984).Google Scholar

52. In modern philosophy of science this view has been particularly emphasized by Karl R.Popper, who called his autobiography, Unended Quest(LaSalle, 111.: Open Court, 1976) (a reprint of “Autobiography of Karl Popper,” in Paul Arthur Schilpp, The Philosophy of Karl Popper[LaSalle, 111.: Open Court, 1974]).See, for example, p.131: “This is why the evolution of physics is likely to be an endless process of correction and better approximation.And even if one day we should reach a stage where our theories were no longer open to correction, since they were simply true, they would still not be complete–and we would know it.For Goedel's famous incompleteness theorem would come into play: in view of the mathematical background of physics, at best an infinite sequence of such true theories would be needed in order to answer the problems which in any given (formalized) theory would be undecidable.” Stephen Hawking is notorious for holding the opposed view that we will soon achieve knowledge of all the fundamental equations of reality.

53. On this distinction with respect to the differences between medieval and modern philosophy, see my“Is Contemporary Jewish Philosophy Possible?–No,” in Studies in Jewish Philosophy: Collected Essays of the Academy for Jewish Philosophy, 1980–1985, ed.Norbert, M.Samuelson, (Lanham, Md.: University Press of America, 1987), pp.17–28.Google Scholar

54. Hokhmot;plural of hokhmah.

55. Gersonides, Wars of the Lord6.i.15.In the Leipzig, 1866 edition of the Wars(reprint: Berlin, 1923), the passage appears on p.356.

56. The idea is repeated frequently in Gersonides' commentary on Song of Songs.See, for example, the following comment on 1:2: “The third impediment–our ignorance of the way that leads to perfection–will also be overcome in this fashion.This is so because while each of those who endeavor to achieve this apprehension by themselves will either apprehend nothing or very little, when what all of them have apprehended is gathered together, a worthy amount will have been gathered.Either by virtue of himself or by virtue of his directing those who see their words towards the achievement of the truth in this.Therefore, one must always be aided in one's research by the words of those who preceded him, especially when the truth in them has been revealed to those who preceded him, as was the case during the time of this sage, for the sciences were then greatly [perfected] in our nation.The matter being so, our perfected predecessors guide us in speculation in a way which brings us to perfection, either through their speech or writing, by virtue of the natural desire they have for proffering this influence, and will make known to us concerning each thing the way in which it should be researched, and what they have understood concerning it, together with the assistance [concerning it] which they have derived from their predecessors.”

57. This understanding of scientific progress is unfashionable today, and derided as “whiggish” by many students of the history of science circles.By imputing this view to Gersonides (and, as shall be seen, Maimonides) I do not mean to express either approval or disapproval of it.See further above, note 1.

58. The reason for this, I think, is that pre-Baconian science was largely deductive, not inductive.Starting out from a limited number of axioms, the number of useful and interesting theorems which can be deduced must be finite.Gersonides gives plenty of evidence that he conducted research into astronomy and even biology inductively, but his overall intellectual framework was deductive.

59. This is, as I understand it, the stereotype of pre-Galilean medieval science; how closely, if at all, that stereotype fits the facts I cannot say.This is also the view of science held by the ancien regimein Isaac Asimov's Foundation.For a discussion of the extent to which this stereotype matched reality, seeAvi-Yonah, Reuven S., “Ptolemy vs.Al-Bitruji: A Study of Scientific-Decision Making in the Middle Agts,”Archives Internationales d'Histoire des Sciences 35 (1985): 124–47.Google Scholar

60. See the texts cited above from Guide2.22 and 24 (in the text between nn.39 and 40).

61. Progress in the sciences (in the Gersonidean sense of the term as we are using it here), it should be noted, was not always assumed by medieval thinkers.Maimonides' fellow Cordovan Averroes thought that humanity had regressed in astronomy from the time of Aristotle.SeeKraemer, Joel L., “Maimonides on Aristotle and Scientific Method,” in Moses Maimonides and His Time, ed.Eric, L. Ormsby (Washington: Catholic University of America Press, 1989), pp.53–88 (p.81) (=Studies in Philosophy and the History of Philosophy19).For Averroes' Aristotelianism in astronomy, see Charles Genequand, Ibn Rushd's Metaphysics(Leiden: Brill, 1984), p.178.Further on this subject, see the sources cited by Reuven S.Avi-Yonah, “Ptolemy vs.Al-Bitruji: A Study of Scientific-Decision Making in the Middle Ages” (previous note), p.125 (n.3); see also Bernard R.Goldstein, “Towards a Philosophy of Ptolemaic Planetary Astronomy,” Ancient Philosophy5 (1985): 293–303 (p.301).For an important discussion of the exact nature of Averroes' position, see A.I.Sabra, “The Andalusian Revolt Against Ptolemaic Astronomy: Averroes and al-Bitruji,” in Transformation and Tradition in the Sciences: Essays in Honor of 1.Bernard Cohen,ed.Everett Mendelsohn (Cambridge, Mass.: Cambridge University Press, 1984), pp.133–153.Google Scholar

62. Maimonides asserts that he is living on the eve of the messianic era and may even have meant it.For details, see my “A Suggestion Concerning Maimonides' Thirteen Principles and the Status of Non-Jews in the Messianic Era,” in Turn–Oranim Studies in Jewish Thought: Simon Greenberg Jubilee Volume,ed.Meir Ayali (Tel Aviv: Ha-Kibbutz ha-Meuhad, 1986), pp.249–260, n.35 (Hebrew).

63. In “Astronomy and Physics in Maimonides' Mishneh Torahand Guide of the Perplexed.”

64. A “complete” science would be one which could be presented in the manner laid down by Aristotle in the Posterior Analytics:a finite number of axioms from which all true knowledge taught by that science could be derived.For the impact of this position on medieval Jewish philosophy, see, for example, Joseph Albo, Sefer ha-Ikkarim1.17 and Isaac Abravanel, Rosh Amanah,chap.23 (in my translation [above, n.5] p.194); see further my discussion in “The Conception of Torah as a Deductive Science in Medieval Jewish Thought,” Revue des eétudes juives146 (1987): 265–279.For Maimonides' reasons for reaching the conclusion that astronomy and metaphysics are uncompletable, see my “Maimonides and Gersonides on Astronomy and Metaphysics.” In that article I show that in order to make his synthesis of religion and philosophy possible, Maimonides was forced to claim that the science of astronomy can never be brought to perfection or closure.What humans can know of astronomical phenomena does not accord with the true (unknowable) facts; rather, astronomical knowledge is only a model which allows us to make predictions, while telling us nothing about the true state of the heavens.This instrumentalist stance in science, I further argue, is a consequence of Maimonides' theory of divine attributes, just as Gersonides' realism in science is connected to his theory of divine attributes.If astronomy, the science of the motions of the heavenly bodies, is uncompletable, then metaphysics, the science which, inter alia,deals with the incorporeal moversof the heavenly bodies, is a fortioriincompletable