Canonical analysis of two convex polyhedral cones and applications

Canonical analysis of two convex polyhedral cones consists in looking for two vectors (one in each cone) whose square cosine is a maximum. This paper presents new results about the properties of the optimal solution to this problem, and also discusses in detail the convergence of an alternating least squares algorithm. The set of scalings of an ordinal variable is a convex polyhedral cone, which thus plays an important role in optimal scaling methods for the analysis of ordinal data. Monotone analysis of variance, and correspondence analysis subject to an ordinal constraint on one of the factors are both canonical analyses of a convex polyhedral cone and a subspace. Optimal multiple regression of a dependent ordinal variable on a set of independent ordinal variables is a canonical analysis of two convex polyhedral cones as long as the signs of the regression coefficients are given. We discuss these three situations and illustrate them by examples.     

The rhetorical foundation of philosophical argumentation

The rejection of rhetoric has been a constant theme in Western thought since Plato. The presupposition of such a debasement lies at the foundation of a certain view of Reason that I have called propositionalism, and which is analyzed in this article. The basic tenets of propositionalism are that truth is exclusive, i.e. it does not allow for any alternative, and that there is always only one proposition which must be true, the opposite one being false. Necessity and uniqueness are the ideals of propositionalism. But the question of the necessity of such a necessity is bound to arise. Foundationalism and propositionalism are intrinsically related. Since necessity excludes alternatives, rhetoric, which is based on the possibility of opposite standpoints, is unavoidably devalued as the crippled child of Reason, identical to sophistry or eristic. But propositionalism cannot justify itself and provide a justification for its own foundation without circle or contraditction. Since it responds to the problem of eradicating problems and alternatives through propositional entities, propositionalism is ultimately based on questioning to which it replies in the mode of denial. The unavowed foundation of Reason is therefore the question of questioning, even though this very question is suppressed as propositionalism. The trace of such a question is not only historical, but can also be seen, for instance, in the role played by the principle of contradiction in the constitution of propositional Reason (Artitotle): opposite propositions are not the expression of a problematic situation, they are either possible or successively unique propositions.We want to replace propositionalism by problematology which allows for the conceptualization of alternatives, thereby rendering a true rhetoric possible. Argumentation cannot then be equated with eristic any more, as propositionalism maintained.Rationality must be seen as having questioning as its true starting-point. Reason must be rhetorical if it is to survive the death of propositionalism which took place after the radical criticisms of Marx, Nietzsche and Freud. Even if it is still hard ffor philosophers and rhetoricians to think within another framework and even though they prefer endlessly to deconstauct the old one instead of changing it, problematology is bound to impose itself as the new voice for rationality, because Reason has always endeavored to solve problems. Propositionalism has been only one way of conceiving problems, based on the view that solutions could be but the suppression of questioning.     

On the Relation Between Time Perception and the Timing of Motor Action: Evidence for a Temporal Oscillator Controlling the Timing of Movement

Studies of time estimation have provided evidence that human time perception is determined by an internal clock containing a temporal oscillator and have also provided estimates of the frequency of this oscillator (Treisman, Faulkner, Naish, & Brogan, 1992; Treisman & Brogan, 1992). These estimates were based on the observation that when the intervals to be estimated are accompanied by auditory clicks that recur at certain critical rates, perturbations in time estimation occur. To test the hypothesis that the mechanisms that underlie the perception of time and those that control the timing of motor performance are similar, analogous experiments were performed on motor timing, with the object of seeing whether evidence for a clock would be obtained and if so whether its properties resemble those of the time perception clock. The prediction was made that perturbations in motor timing would be seen at the same or similar critical auditory click rates. The experiments examined choice reaction time and typing. The results support the hypothesis that a temporal oscillator paces motor performance and that this oscillator is similar to the oscillator underlying time perception. They also provide an estimate of the characteristic frequency of the oscillator.     

Book reviews and notes

GENERAL.

READINGS IN THE QUR'AN. Selected and translated by KENNETH CRAGG. London: Collins Liturgical Publications, 1990. 389pp. Pb. £8.95. ISBN 0–00–599087–4.

DER KORAN UND DIE JUDEN: DIE GESCHICHTE EINER TRAGODIE. By Johan Bouman. Darmstadt: Wissenschaftliche Buch‐gesellschaft, 1990. 130pp. Pb. n.p. ISBN 3–534–80123–7.

ISMAIL HAKKI BURSEVPS TRANSLATION OF AND COMMENTARY ON FUSUS AL‐HKAM. VOLS. 3 and 4. By Muhyiddin Ibn Arabi. Translated by Bulent Rauf with the help of R. Brass and H. Tollemache. Oxford: Muhyiddin ibn ^cArabi Society, 1989, 1991. 254pp, 353pp. Hb. £40.00, £50.00. ISBN 0–9509527–2–9; 0–9509527–4–5.

SCIENCE AND MUSLIM SOCIETIES. By Nasim Butt. London: Grey Seal Books, 1991. 135pp. Pb. £5.95. ISBN 1–85640–023–9.

THE MUSLIMS OF AMERICA. Edited by Yvonne Yazbeck Haddad. Oxford: Oxford University Press, 1991. 249pp. Hb. £35.00. ISBN 0–19–506728–2.

TURNING POINTS IN RELIGIOUS STUDIES. By URSULA KING. Edinburgh: T & T Clark Ltd, 1990. 329pp. Hb. £19.95. ISBN 0–567–09564–9.

THE SEPARATED ONES: JESUS, THE PHARISEES AND ISLAM. By Ruqaiyyah Waris Maqsood. London: SCM Press, 1991. 194pp. Pb. £9.95. ISBN 0–334–02498–6.

WHO NEEDS AN ISLAMIC STATE! By Abdelwahab El‐Affendi. London: Grey Seal Books, 1991.115pp. Pb. £5.95. ISBN 1–85640–022–0.

‘MULTI‐FAITH WORSHIP'? QUESTIONS AND SUGGESTIONS FROM THE INTER‐FAITH CONSULTATIVE GROUP. By The. General Synod Board of Mission. London: Church House Publishing, 1992. 66pp. Pb. £3.50. ISBN 0–7151–5530‐X.

WAS SAGT DER KORAN ZUM HEILIGEN KRIEG? By Adel TheodorKhoury. Giitersloh: Gutersloher Verlaghaus Gerd Mohn, 1991. 95pp. Pb. DM12.80. ISBN 3–579–00787–0.

REGIONAL.

Africa.

RELIGION AND CUSTOM IN A MUSLIM SOCIETY: THE BERTI OF SUDAN. By Ladislav Holy. Cambridge Studies in Social and Cultural Anthropology. Cambridge: Cambridge University Press, 1991. 243pp. Hb. £30.00; $49.50. ISBN 0–521–39485–6.

POPULAR ISLAM IN TUNISIA. By Kees Schilder. Research Reports 1991/44. Leiden: African Studies Centre, 1991. 171pp. Pb. DFL.12.50. ISBN 90–70110–85–7.

A POEM CONCERNING THE DEATH OF THE PROPHET MUHAMMAD UTENDI WA KUTA WAFUNABII. Edited by J.W.T. Allen, Rland Allen, N.Q. King, Jan Knappert Et Al. African Studies, 26. New York/Ontario/Larnpeter: The Edwin Mellen Press, 1991. 161pp. Hb. n.p. ISBN 0–7734–9705–6.

SACRED VOID: SPATIAL IMAGES OF WORK AND RITUAL AMONG THE GIRIAMA OF KENYA. By David Parkin. Cambridge Studies in Social and Cultural Anthropology. Cambridge: Cambridge University Press, 1992. 259pp. Hb. £35.00. ISBN 0–521–40466–5.

PEOPLE AND EMPIRES IN AFRICAN HISTORY: ESSAYS IN MEMORY OF MICHAEL CROWDER. Edited By J.F. Ade Ajayi and J.D.Y. Peel. London and New York: Longman, 1992. 254pp. Hb. £36.00. ISBN 0–582–08997–2.

Asia.

MUSLIMS IN CENTRAL ASIA: EXPRESSIONS OF IDENTITY AND CHANGE. By Jo‐ANN GROSS. Durham: Duke University Press, 1992. 224pp. Pb. $18.95. ISBN 0–8223–1190–9.

Europe.

ISLAM IN DUTCH SOCIETY: CURRENT DEVELOPMENTS AND FUTURE PROSPECTS. Edited by W.A.R. Shadid and P.S. Van Koningsveld. Kampen. Kok Pharos Publishing House, 1992. 205pp. Pb. n.p.ISBN 90–242–3047–0.

VAN MAT TOT MINARET. By Nico Landman. Amsterdam: VU Uitgeverij, 1992. 387pp. Pb. n.p. ISBN 90–5383–086–3.

DE ISLAM IN WEST‐EUROPA, IN HET BIJZONDER IN NEDERLAND. By HuUG Van Ooijen, Rinus Penninx, Jan Rath and ThulSunier. Nijmegen: Reeks REcht & Samenleving, 1991. 76pp. Pb. n.p. ISBN 90–71478–20–3.

MUSLIMS IN WESTERN EUROPE. By Jorgen S. Nielsen. Islamic Surveys 20. Edinburgh: Edinburgh University Press, 1992. 186pp. Hb. £25.00. ISBN 0–7486–0309–0.

NATIONAL PROBLEMS IN THE BALKANS: HISTORY AND CONTEMPORARY DEVELOPMENTS. Edited by V. Mincheva. Sofia: Arges Publishing House for the Institute of Balkan Studies, 1992.247pp. Pb. LV20,00. No ISBN.

THE BALKANS: MINORITIES AND STATES IN CONFLICT. By Hugh Poulton. London: Minority Rights Publications, 1991. 244pp. Pb. £8.95. ISBN 1–873194–05–6.

THE SATANIC VERSES: BRADFORD RESPONDS. Edited by David G. Bowen. Bradford: D.G. Bowen and Bradford & Ilkley Community College, 1992. 82pp. Pb. .n.p. ISBN 0–947–851–25–9.

THE KINGDOM OF CYPRUS AND THE CRUSADES 1191–1374. By Peter W. Edbury. Cambridge: Cambridge University Press, 1991.241pp. Hb. £27.50, $44.50. ISBN 0–521–26876–1.

DIE MIGRANTEN AUS SUBAY: TURKEN IN DEUTSCHLAND: EINE ETHNOGRAPHIE. By Werner Schiffauer. Stuttgart: Klett‐Cotta, 1991. 388pp. Hb. n.p. ISBN 3–608–93170–8.

Middle East.

POLITICAL ISLAM: RELIGION AND POLITICS IN THE ARAB WORLD. By Nazih N. Ayubi. London and New York: Routledge, 1991. 291pp. Hb. £40.00. ISBN 0–415–05442–7.

THE ARAB CHRISTIAN: A HISTORY IN THE MIDDLE EAST. By Kenneth CRAGG. London: Mowbray, 1992. 336pp. Pb. £9.95. ISBN 0–264–67257–7.

ISLAMIC FUNDAMENTALISM AND THE GULF CRISIS. Edited by JAMES PISCATORI. Chicago: The University of Chicago Press, 1991. 267pp. Pb. £7.95; $11.50. ISBN 0–9629608–0–2.

RACE AND SLAVERY IN THE MIDDLE EAST. By BERNARD LEWIS. Oxford: Oxford University Press, 1990. 184pp. Hb. £22.50. ISBN 0–19–506283–3.

THE IRAQI REVOLUTION OF 1958: THE OLD SOCIAL CLASSES REVISITED. Edited by Robert A. Fernea and Wm. Roger Louis. London: I.B. Tauris, 1991. 232pp. Hb. £35.00. ISBN 1–85043–318–6.

CULTURE, HISTORY AND IDEOLOGY IN THE FORMATION OF BA'THIST IRAQ, 1968–69. By AMATZIABaram. New York: St Martin's Press, 1991. 196pp. Hb. £35.00. ISBN 0–312–04805‐X.

THE PALLESTINIAN UPRISING: A WAR BY OTHER MEANS. By F. Robert Hunter. London: I.B. Tauris, 1991.292pp. Hb. £17.95. ISBN 1–85043–325–9.

POLITICS IN AN ARABIAN OASIS: THE RASHIDI TRIBAL DYNASTY. By Madawi AL Rasheed. London: I.B. Tauris, 1991. 300pp. Hb. £35.00. ISBN 1–85043–320–8.

THE LION OF EGYPT: SULTAN BAYBARSI AND THE NEAR EAST IN THE TfflRTEENTH CENTURY. By Peter THORAU. London: London and New York, 1987. 319pp. Pb. £13.50. ISBN 0–582–06823–1.

HISTORICAL DICTIONARY OF LIBYA. By RONALD BRUCE ST JOHN. African Historical Dictionaries, 33.2nd Edition. Metuchen, NJ & London: Scarecrow Press, 1991. 192pp. Hb. £18.75. ISBN 0–8108–2451–5.

ACCOMMODATING PROTEST: WORKING WOMEN, THE NEW VEBLING AND CHANGE IN CAIRO. By ARLENE ELOWE MACLEOD. New York: Columbia University Press, 1991. 206pp. Hb. $37.50. ISBN 0–231–07280–5.

FEZ: CITY OF ISLAM. By Titus Burckhardt. Cambridge: Islamic Texts Society, 1992. 175pp. Hb. £24.95; $39.95. ISBN 0–946621–17–9.

CHRISTIAN‐MUSLIM RELA TIONS.

ROBIN LAMBURN — FROM A MISSIONARY'S NOTEBOOK: THE YAO OF TUNDURU AND OTHER ESSAYS. Edited by NOEL Q. KING and Klaus Fiedler with Gavin White. Social Science Studies on International Problems, no. 164. Saarbriicken; Fort Lauderdale: Verlag Breitenbach, 1991. 240pp. Pb. n.p. ISBN 0584–603‐X.

MATERIAUX POUR SERVIR A L'ETUDE DE LA CONTROVERSE THEOLOGIQUEISLAMO‐CHRETIENNE DE LANGUE ARABE DU Vffle AUX Xlle SIECLE. By PAUL KHOURY. Religionswissenschaftliche Studien 11/2. Wurzburg: Echter Verlag and Altenberge: Oros Verlag, 1991. 633pp. Pb. $633.00; DM99.80. ISBN 3–429–01410–7 (Echter); 3–89375–039–8 (Oros).

THE CONQUEST OF CHRISTIAN AND MUSLIM SPAIN 1031–1157. By Bernard F. Reilly. Oxford: Blackwell, 1992. 284pp. Hb. £40.00. ISBN 0–631–16913‐X.

ISLAM IN A WORLD OF DIVERSE FAITHS. Edited by Dan Cohen‐Sherbok. Library of Philosophy and Religion. Basingstoke: Macmillan, 1991. 218pp. Hb. £45.00. ISBN 0–333–52612–0.

LA FOIE EN MARCHE: LES PROBLEMES DE FOND DU DIALOGUE ISLAMO‐CHRETIEN. By PONTIFICIOISTITUTO Dl STUDI Arabie D'islamistica. Collection ‘Studi Arabo‐Islamici del PISAF, no.4. Rome: PISAI, 1990. 235pp. Pb. n.p. ISBN 88–85907–05–9.

DIPLOMATARIUM II: DOCUMENTS 1–500: FOUNDATIONS OF CRUSADER VALENCIA: REVOLT AND RECOVERY 1257–1263. By ROBERT I. Burns. Princeton: New Jersey, 1991. 440pp. Hb. $69.50. ISBN 0–691–05435–5.

ANTI‐CHRISTIAN POLEMIC IN EARLY ISLAM: ABU ‘ISA AL‐WARRAQ'S ‘AGAINST THE TRINITY’. By David Thomas. University of Cambridge Oriental Publications 45. Cambridge: Cambridge University Press, 1992. 218pp. Hb. £40.00; $74.95. ISBN 0–521–41244–7.

INCULTURATION ET LIBERATION EN AFRIQUE AUJOURDHUI: MELANGES EN L'HONNEUR DU PROFESSEUR ABBE MULAGO GWA CKALA. Revue Africaine de Theologie, 27–28, April‐October 1990. 336pp. No ISBN number.

STRIVING TOGETHER: A WAY FORWARD IN CHRISTIAN‐MUSLIM RELATIONS. By Charles Kimball. Maryknoll: Orbis Books, 1991. 132pp. Pb. n.p. ISBN 0–88344–691‐X.

INTERWINED WORLDS: MEDIEVAL ISLAM AND BIBLE CRITICISM. By Hava Lazarus‐Yafeh. Princeton University Press, 1992. 178pp. Hb. £22.50; $29.95. ISBN 0–691–07398–8.     

Comparative analysis of actual and mental movement times in two graphic tasks

This study compared the temporal organization of graphic movements executed either actually or mentally. Six subjects had to perform two tasks, writing a sentence and drawing a cube, either as a real performance or as an imagined one, with either the right or the left hand, and with either a small or a large tracing amplitude. In the same subject, for the same hand, mental and actual movement times were both very stable and very close from trial to trial regardless of the tracing amplitude. Thus, mental movements mimic closely real movements in their temporal organization and are likely to involve the same planning program.     

The applicability of verbal mnemonics for different populations: A review

The main aims of this review were to assess(1) the likelihood of learners making spontaneous use of verbal mnemonics, and (2) the extent to which learners will benefit from using verbal mnemonics. Over 60 investigations of verbal mnemonics were reviewed, most of which concentrated upon sentence mnemonics or first-letter mnemonics; although many of the studies used students as subjects, the review also considers the value of verbal mnemonics for schoolchildren, mentally handicapped people, brain-injured patients, and the elderly. On the whole, verbal mnemonics are relatively popular internal memory aids and, when compared to standard control conditions such as rehearsal, appear to be effective learning strategies for most of the populations studied, although mentally handicapped people and schoolchildren may find it difficult to produce effective mnemonics themselves; additionally, students and schoolchildren can benefit from the use of mnemonic sentences as part of more complex techniques. Comparisons between verbal mnemonics and other memory-aiding strategies have, however, given more equivocal results. A number of areas for future research are identified. In particular it is hoped to see a development of recent trends to use non-student subject, and to investigate the applicability of verbal mnemonics outside the laboratory.