William of Ockham

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Wilhelm von Ockham, sketch from a manuscript of Summa logicae made in 1341

Wilhelm von Ockham , English William of Ockham or Occam (* around 1288 in Ockham in the county of Surrey , England ; † April 9, 1347 in Munich ), was a famous medieval philosopher , theologian and ecclesiastical writer in the late Scholastic era . Traditionally, but imprecisely, he is called one of the main representatives of nominalism . His extensive philosophical work includes works on logic , natural philosophy , epistemology , philosophy of science , metaphysics , ethics and political philosophy .


While the sources - especially Ockham's own works - provide detailed information about his views and teachings, there is only relatively sparse information about his personality and biography.

Youth, training, teaching

Quaestiones in quattuor libros sententiarum

The first certain date in Occam's life is his ordination as a subdeacon at Southwark in February 1306; at that time he was already a member of the Franciscan order . Around the period from 1300 to 1308 he received his training in the Artes at a religious school ( study , study house) of the Franciscans in London as a prerequisite for the study of theology, which he then began around 1308 at Oxford University . Around 1317 he received the degree of a bachelor's degree there and thus the right to hold a lecture on the sentences of Petrus Lombardus . However , he apparently never obtained the master's degree , as his medieval nickname Venerabilis Inceptor ("Venerable Beginner") means that he had qualified for the master's degree, but it was not formally awarded to him. The reasons for this were possibly university-political conflicts and philosophical-theological contradictions, but it could also have been due to the fact that the number of admissible degrees in the doctoral procedure was limited from the outset to the number of positions to be filled at the university and in the religious houses. In any case, Ockham left Oxford and moved to London, where he taught in the Franciscan study house from around 1320.

Defense against accusation of heresy

The Chancellor of Oxford University, Magister John Lutterell , found himself in a violent conflict with the Magister there at the beginning of the 1320s. In the summer of 1322, the magisters asked the responsible Bishop of Lincoln to depose the chancellor. Lutterell was released. Whether Ockham already played a role in this conflict is not clear from the sources, but it can be assumed because the Chancellor, as an avid Thomist, was a resolute opponent of the philosophy and theology of the Franciscan scholar. In any case, King Edward II permitted Lutterell to travel to the papal court in Avignon in August 1323 . There the former chancellor presented an indictment against Ockham, in which he accused him of heresy . Ockham then had to go to Avignon in 1324 to face the trial against him. Lutterell's indictment listed 56 doctrines that were denounced as errors. In 1325 a commission was set up to investigate the case. It consisted of six theologians, including the accuser Lutterell. On the basis of the indictment, the commission compiled a new list of 51 allegedly heretical theses by Ockham. In 1326 the commission drew up a final report in which 29 of the 51 sentences of Ockham were described as heretical or erroneous, the remaining 22 as possibly wrong. Among other things, Ockham was found guilty of Pelagianism . This would have his condemnation by Pope John XXII. nothing more stood in the way, especially since the Pope had already spoken out sharply against Occam's teaching in a letter to Edward II in the summer of 1325. Although the trial was carried out very carefully and at great expense, and Ockham remained as a defendant in Avignon until 1328, no verdict was reached for reasons unknown. Ockham was not in custody as a defendant in Avignon; he had to stay there, but was allowed to move around and work on his defense.

Break with the Pope and fight for the Emperor

William of Ockham on a church window in Surrey

At that time the poverty struggle was going on, a theological argument unrelated to the indictment against Ockham. The original question was to what extent the Franciscans were obliged to live in complete poverty in the sense of the will of the founder of the order, Francis of Assisi , and how the Franciscan order should deal with gifts - especially real estate - that it received and those with the the original ideal of poverty were difficult to reconcile. It was also disputed whether Christ and the apostles owned privately or collectively property; from the assumption that this had not been the case, it was inferred that consistent following of Christ was necessarily associated with corresponding poverty. Accordingly, the monks were not allowed to own any things, either individually or collectively, but only to use them to an unavoidable extent. Although formally the dispute only related to the way of life of begging monks, the poverty demand could also be understood as a criticism of the wealth of the higher clergy and especially of the members of the papal court.

Pope John XXII. was a staunch opponent of the poverty thesis and condemned it as heretical. As a result, he came into conflict with the order general of the Franciscans, Michael of Cesena , whom he cited to Avignon. Michael arrived in Avignon on December 1, 1327; he probably lived there in the Franciscan convent, where Ockham was also housed. Ockham, who had previously concentrated on theological and philosophical questions and had hardly made any appearances in terms of church politics, saw himself compelled to deal with the poverty struggle. Michael succeeded in convincing the philosopher of the opinion that the poverty demand was justified and that three opposing ordinances of the Pope from 1322 to 1324 were heretical. The two Franciscans drew the conclusion from this that the Pope had fallen away from the true faith. John forbade Michael to leave Avignon. On May 26, 1328 Michael, Wilhelm von Ockham and the Franciscans Bonagratia von Bergamo and Franz von Marchia fled Avignon and went to Pisa by sea . There they met Emperor Ludwig IV the Bavarian , who at that time was already in dispute with the Pope. Johannes had denied the legality of Ludwig's rule and excommunicated him on March 23, 1324 , whereupon Ludwig accused the Pope of heresy and declared him deposed on April 18, 1328. The poverty dispute, in which Ludwig was on the side of the proponents of poverty from 1324, played a role in the accusation of heresy. Ludwig placed the fugitive Franciscans under his protection; At the beginning of 1330, Ockham and his companions arrived in Munich, where he stayed until his death. Ockham, who had been excommunicated on July 20, 1328, now became a champion of the Pope's opponents. He began to deal intensively with fundamental political and canonical questions, in particular the relationship between secular and spiritual power and the limits of the Pope's powers.

The rebellious monks did not succeed in winning their order for the fight against John; the Franciscans remained loyal to the Pope and elected a new general . Even after the Pope's death in 1334 there was no reconciliation with his successor Benedict XII. ; the positions remained essentially unchanged, and Ockham wrote a treatise against Benedict in order to also prove the new Pope to be a heretic. Although Ockham was able to consolidate his position as advisor to the emperor - he also helped Ludwig in the marital dispute over Margaret of Tyrol with an expert opinion - the decline of Ludwig's reputation and power and the election of the anti-king Charles IV in July 1346 meant for the excommunicated Franciscan an acute danger. One of his last texts shows that he was counting on the possibility of Munich falling into the hands of the opponents. Ockham did not live to see Ludwig's death in October 1347. Contrary to earlier assumptions, according to which he lived until 1349 and possibly reconciled with the Pope, according to current research it is certain that he died in April 1347 as an excommunicated person.


Beginning of the Summa logicae in the 1341 manuscript Gonville and Caius College (Cambridge) 464/571

The works of Occam can be divided into four main groups:

  • Writings on logic: This includes Ockham's commentaries on ancient works that were counted in the late Middle Ages to the "old" (since time immemorial) logic ( logica vetus ) (the categories and de interpretatione from the Aristotelian Organon and the Isagogue of Porphyrios ), and his Commentary on the sophistic refutations of Aristotle, which belonged to the “new” (only later known) logic ( logica nova ). In addition to these commentary writings, Ockham also wrote the systematically structured Summa logicae , a comprehensive overall presentation of the state of knowledge of his time - both the ancient tradition and medieval innovations - in the field of logic, as well as smaller writings.
  • Natural philosophical writings in which Ockham deals with the physics of Aristotle.
  • Theological works: By far the largest and most important of them is the Sentences Commentary, Ockham's commentary on the four books Sententiae by Petrus Lombardus , a systematic presentation of the entire theology from the 12th century. Of the four books in this commentary, only the first is available in a version authorized by the author; the others are lecture notes.
  • Political writings: While the works of the three other groups were almost all written before Ockham's break with the Pope and his flight from Avignon, the political works belong to the last phase of his life, the time in Munich. They deal with questions of state theory and legal philosophy and serve in particular the fight against the curia .


Three basic principles, which Ockham consistently applies everywhere, shape his thinking in both theological and philosophical fields:

  • the idea that everything that exists in the world is not necessary as such, but is contingent (principle of contingency )
  • Aristotle requirement of consistency (contradiction principle), which over the area of the logic addition, in Occam also implications in the ontology and theory of knowledge leads
  • the principle of thrift, the demand for the most economical use of theoretical assumptions. This methodological principle is known under the popular and often misunderstood name " Ockham's razor ".


Ockham turned against the neesessitarianism (theory of necessity) that prevailed in ancient and previous medieval thought, originally formulated by Plato and also represented by Aristotle . Plato was of the opinion that the existing world order inevitably results from the interaction of necessity and reason exactly as it is empirically given. Aristotle also considered everything that actually existed to be necessary and believed that everything was optimized by nature as far as possible. Ockham counters this with his conviction of the contingency of the world and all of its components. For him the world is only one of an unlimited number of possible worlds that God could have created. Moreover, having created the world, God can change or abolish natural laws at any time, and there is no apparent reason for him to do or fail to do so. This view is sometimes interpreted to mean that Ockham's God acts arbitrarily, that is, gives preference to one possibility over others for no rational reason. But that's not what Ockham meant, because from his point of view that would be an inadmissible assessment of God's actions from a limited human perspective. Ockham regards God's actions as rational, but only partially visible to human reason. The question of why the world is so and not different must therefore remain open.

Exclusion of objection

One of the main demands of Aristotelian logic is the principle of contradiction , according to which it is impossible that the same thing should and should not belong to it in the same relation. Ockham emphasizes that something contradicting itself in this sense is not only illogical, but also cannot be an object of knowledge and absolutely cannot exist. In doing so, he limits the omnipotence of God, whose limitlessness he otherwise attaches great importance to. For God, too, there are therefore only consistent alternatives, since he can only create in an orderly manner within this framework. Ockham differentiates conceptually (not real) between an absolute and an “ordered” or “ordained” power of God and states that God only acts according to the rules of a self-determined order that excludes contradicting acts. Other orders that God could have established should also be free of contradictions. However, Ockham does not give a reason why God cannot achieve contradictions. He considers it impossible for God to create something really infinite or a spatially extended indivisible body, to undo something that has already happened, or to create real universals, because he is convinced that all this would violate the principle of contradiction. For Ockham, however, it is theoretically possible for God to sin.

The parsimonious principle

The parsimonious principle (lat. Lex parsimoniae ) says that unnecessary multiplication should be avoided in statements: "In vain happens with the help of a majority what can be achieved with less" and "A majority cannot be assumed without necessity". With this, Ockham wants to prevent the creation and use of superfluous conceptual instruments from contributing to the emergence of ontological ideas that are not helpful for scientific knowledge. In the phrase “free of charge with the help of a majority, what can be achieved by one thing”, the principle occurs as early as the 13th century with the Franciscan Odo Rigaldus, a student of Alexander von Hales .

As a justification, Ockham cites Aristotle, who in his physics speaks out against the assumption of an infinite variety of principles. Aristotle argues that otherwise there can be no knowledge of what follows from the principles; moreover, the adoption of a limited number of principles could accomplish anything that could be achieved by an infinite number. However, Ockham goes far beyond what Aristotle meant. Aristotle only thinks that an unlimited variety of principles should not be assumed, while Ockham strictly demands the elimination of all unnecessary hypotheses or theoretical components.

Occam's God is not bound by the thrift principle; rather, there is much that he does with greater effort for an unknown reason, although he could do it with less effort. The philosopher is not entitled to eliminate something possibly existing on the grounds that it is superfluous. However, in his own activity, the formulation of statements, he should not introduce more assumptions than he actually needs. This thrifty principle does not contain the assertion that the world is constructed as sparingly as possible and therefore that there is no unnecessary existence in it, but it is a pragmatic expediency rule for the scientific description of phenomena. If a statement violates the principle of economy, it does not follow that it is untruthful, but only that it is not appropriate to the goal of scientific knowledge. Ockham expresses this with formulations like "it is not necessary" or "there is no need at all".

Numerous modern authors, including Leibniz , quote the principle known as " Ockham's razor " in the formulation: "Entia non sunt multiplicanda sine necessitate": " Entities (things assumed to be) should not be unnecessarily multiplied". This formulation, attested only since the 17th century, does not come from Ockham. Ontologically , the principle, also known as the principle of thrift, means, according to a widespread interpretation in modern times, that things should only be considered to exist if there is a need to assert their existence; the "superfluous" things are to be "shaved off" as nonexistent. Ockham did not mean that and did not express it in that way; for he was not concerned with the being or non-being of things, but with the justification of statements. Nor did he use the term “razor”.


The view of Aristotle that knowledge presupposes sensory perception, Ockham shares only with regard to the sensually perceptible objects of knowledge of the outside world, but not with regard to the knowledge related to one's own acts of intellect. For him, the impetus for knowledge always comes from the particular thing ( singular ). He rejects the view of Thomas Aquinas , according to which an independent mediating medium, the spiritual form of knowledge ( species intelligibilis ), must stand between the individual thing and the act of knowledge . He also rejects the widespread view that knowledge is based on the fact that the intellect assimilates itself to the object of perception (assimilation) and that this is represented in it (representation), which presupposes a structural similarity between them (affinity). On the other hand, he argues that this must lead to an infinite regress , since the representation, in order to be able to be an object of knowledge, in turn needs a representation.

Ockham emphasizes that something can only be known if it has the form of a sentence ( complexum ), i.e. a logical connection between what is said about something (subject term) and what is said about it (predicate term). For Ockham, such a sentence is only scientific in the proper sense ( proprie ) if its statement is necessarily true, i.e. if its correctness has been checked and proven by a syllogism whose premises are necessary. “Necessary” does not mean an absolute necessity of the external state of affairs to which the proposition refers (that would make science impossible in Ockham's contingent world), but only the validity of the proposition, provided that the two terms are intended to combine meaningfully. The objects of a science are therefore not real objects of the outside world that are independent of thought and which the intellect assimilates in the process of knowledge, but only the sentences that are said about the objects.


Ockham attaches great importance to the clear separation of logical statements and ontological facts. The predication whose subject is a general term that he does not understand the existence of which they express in the predicate property in the general concept, but only as an assignment of subject and predicate in the context of the statement. The predicate belongs to the subject, but does not relate to it like a property to its bearer or an accident to a substance , because the assignment of the terms in the sentence to one another does not reflect a relationship between the real entities to which they refer.

In his propositional logic , Ockham already formulates both de Morgan's laws as axioms for the conjunction “and” and the disjunction “or” .

Ockham believes that future events can occur (that is, be true) even when people do not know they do. In the last third of the 20th century, this way of thinking inspired the development of various calculi of Computation Tree Logic , a form of time logic that is based on a branched sequence of times. In the literature, these calculi are referred to as Ockhamian approaches or Ockhamian logics.


Occam's consistent separation between logical and ontological statements leads him to reject the metaphysics of Thomas Aquinas and especially the Aristotelian notion of an analogia entis represented in Thomism . This is about the question, answered in the affirmative by Thomas, whether the expression “being” can be predicated on different entities such as “God” and “creature” in the same meaning ( univok ), be it in the sense of an analogy (Aristotelian) or in the sense a participation of one being in the other ( Neoplatonic ). Ockham denies this. In his view, the term “being” does not denote a property that actually exists in itself and which could be linked to a real subject like Socrates by saying “Socrates is (or was) a being”. Rather, the statement "Socrates is (or was) a being" is only true because the term "Socrates" (subject) and the term "is being" (predicate) stand for one and the same in the sense of propositional logic (suppose, see supposition ).

The problem of universals , the question of the relation to reality of universals (general terms), was discussed controversially in the Middle Ages since the late 11th century. The opposing views were conceptual realism (also known as universal realism or realism for short) and nominalism . Realists believe that the general terms denote something that also exists extramentally (outside the human mind), namely in the individual things (Aristotelianism) or also independently of these in a world of ideas (Platonism). Nominalists, on the other hand, consider the general terms to be mere signs that occur within the human mind because it needs them for its activity, but beyond that have no relation to any reality. Both the realists and their opponents showed varying degrees of radicalism or moderation with which they represented their positions. Ockham represented a "moderate" nominalism, which is sometimes called conceptualism to differentiate it from the "radical" nominalism of Johannes Roscelin . To avoid confusion with modern conceptualism, one also speaks of “nominalism based on the theory of signs”. The radical, older nominalism of Roscelin - whose radicalism is only known from opposing representations - explains the general terms for mere "names" ( nomina ), i.e. fictions created by the mind, which nowhere have any reality except that they have a "vocal breath" ( flatus vocis ) are. Occam's moderate nominalism or conceptualism, while also denying the existence of universals in the external objects of perception, regards the general concepts as existing insofar as they are concepts that actually exist within the human mind. Accordingly, the general has a subjective, purely mental reality in thought and only there. Ockham accuses the realists of turning linguistic data into realities and of blurring the fundamental difference between existence and predication; About something one says that it exists or does not exist, about general things, on the other hand, that it is said (predicted) or will not be said.

State theory

The nominalistic or conceptualistic way of thinking of Occam also comes into play in his conception of the state. Since the human individual is a single thing that really exists as such, while the citizenry or the state is a universal one that only exists in the human mind, the state cannot be an end in itself or represent a superior value, but its purpose is the good of individual citizens who make it up. The common good, i.e. that which benefits individuals, has priority over arbitrary decisions by state bodies. The criterion for the legitimacy of orders from the authorities is whether they serve the common good or not.

In Occam's view, the emperor derives his competence from the people. The people can only give them the authority to promote the common good, that is, the good of the individuals affected by their orders. It cannot empower a person to diminish the common good or to take action for purposes other than the common good of citizens. If the ruler issues an order that is inconsistent with justice and is not for the common good, he is beyond his jurisdiction and there is no obligation to obey.


Ockham uses the same criteria as in the theory of the state in the doctrine of the church ( ecclesiology ). He is convinced that the office of the Pope also derives its legitimation from the fact that it serves the benefit of all. If the Pope were allowed to do whatever is not forbidden by divine law at will, then, as Ockham writes, all Christians would be his slaves. The pope's power is therefore not only limited by the fact that he must not violate divine law or natural law, but also by his duty to serve the welfare of the individuals under him. In addition, he is usually only responsible for spiritual matters; He may only interfere in the emperor's secular area of ​​competence if he can make it clear that otherwise the common good would be endangered.

Since Ockham considered it proven that the Pope was a heretic, he needed a criterion for truth in matters of faith that was independent of the Pope and that could be used against him. For him this could not be a judgment of a general council , as the conciliarists believed, because he also regarded a council as fundamentally susceptible to error. Although he adhered to the traditional doctrine that the church is the decisive authority with regard to the truth of theological statements, he redefined the term church. At first he spoke of the “Roman” Church, by which he meant the Apostolic See , which he also explicitly named. Later, when he distanced himself from the Curia, he appealed to the judgment of the "universal" Church. He discussed the theoretical possibility that all clerics in the world could be mistaken on one question of faith. In addition, he remarked that in this case lay people, even if they were few and theologically completely uneducated, would have to insist on their point of view; they are then the church and the qualified judges of the clergy. He even thought it possible that the entire Church, except for one person, who may even be an underage child, could fall into false doctrine. Then the true Church consists of that one person. Christ's promise: “I am with you every day until the end of the world” ( Mt 28:20  EU ) guarantees that all Christians can never fall away from the faith at the same time. Therefore a Christian need not despair of his victory even if he is the only orthodox believer standing alone against all. With this, Ockham ultimately assigns, in the extreme extreme case, the task of making the final decision by means of his own judgment.


Although Ockham had a few students, including Adam Wodeham , he did not establish a continuous school of philosophy or theology that was tied to a particular teaching structure. Nevertheless, one speaks of late medieval Ockhamism, and the term "Ockhamists" ( Ockamistae , Occamici ) occurs in medieval sources. This means a nominalist current of the 14th and 15th centuries that referred to Occam's writings. However, some of these philosophers (among them Nikolaus von Autrecourt and Johannes von Mirecourt ) radicalized Ockham's positions, others combined them with opposing views of other thinkers, while the numerous opponents of nominalism partly distorted Ockham's views. This gave rise to a skewed picture of Ockham's philosophy in large circles. The approach of the philosophers, more or less based on Ockham's approach, was referred to as the “modern way” ( via moderna ) to distinguish it from the “old way” of those who, in one way or another, linked general terms with structures independent of thought.

In 1339 the University of Paris banned the reading of Ockham's writings, but their use in class was forbidden. Soon afterwards, a general ban on nominalism was issued there.

In the early modern period , Ockham's works were seldom printed; his teachings were mostly known only from second or third hand. His ideas were theologically stimulating for Luther , who got to know them through a textbook-like summary that the Tübingen professor Gabriel Biel , an Ockhamist, had prepared. Luther fought Biel, but held Ockham in high esteem. In addition to the Franciscan's ecclesiastical activity, he particularly liked the fundamental criticism of the teachings of leading scholastic theologians .

In the modern age, the principle of economy known as “ Occam's razor ” has found appreciation, for example with Charles S. Peirce and Bertrand Russell . Peirce claimed that all of modern philosophy was based on Occamism. In constructivism , especially in radical constructivism , Ockham is seen as an important forerunner of the constructivist approach.

Wilhelm von Ockham is one of the characters that Umberto Eco incorporated into the figure of William von Baskerville in his novel The Name of the Rose . The Occam programming language and Occamstraße in Munich's trendy Schwabing district are named after him.

Text output

Political Writings
  • Guillelmi de Ockham opera politica , University Press, Manchester 1940-1963
    • Vol. 1: Octo quaestiones de potestate papae; to princeps pro suo succursu ... possit recipere bona ecclesiarum, etiam invito papa; consultatio de causa matrimoniali; opus nonaginta dierum (chapters I to VI) , ed. Jeffrey G. Sikes, 1940
    • Vol. 2: Opus nonaginta dierum, capitula 7-124 , ed. Jeffrey G. Sikes / Hilary S. Offler, 1963
    • Vol. 3: Epistola ad Fratres Minores; tractatus contra Ioannem; tractatus contra Benedictum , ed. Hilary S. Offler, 1956
  • Breviloquium de principatu tyrannico , in: Richard Scholz (Ed.): Wilhelm von Ockham as a political thinker and his Breviloquium de principatu tyrannico , Leipzig 1944
Philosophical writings
  • Guillelmi de Ockham opera philosophica et theologica , series Opera philosophica , ed. The Franciscan Institute of St. Bonaventure University , St. Bonaventure (NY) 1974–1988
    • Vol. 1: Summa logicae , 1974
    • Vol. 2: Expositionis in libros artis logicae prooemium et expositio in librum Porphyrii de praedicabilibus; expositio in librum praedicamentorum Aristotelis; expositio in librum perihermenias Aristotelis; tractatus de praedestinatione et de praescientia dei respectu futurorum contingentium , 1978
    • Vol. 3: Expositio super libros elenchorum , 1979
    • Vol. 4: Expositio in libros physicorum Aristotelis: prologus et libri I-III , 1985
    • Vol. 5: Expositio in libros physicorum Aristotelis: libri IV – VIII , 1985
    • Vol. 6: Brevis summa libri physicorum, summula philosophiae naturalis et quaestiones in libros physicorum Aristotelis , 1984
    • Vol. 7: Opera dubia et spuria Venerabili Inceptori Guillelmo de Ockham adscripta , 1988
Theological writings
  • Super IV libros sententiarum. Jean Trechsel, Lyon 1495 digitized
  • Guillelmi de Ockham opera philosophica et theologica , series Opera theologica , ed. The Franciscan Institute of St. Bonaventure University, St. Bonaventure (NY) 1967-1986
    • Vol. 1: Scriptum in librum primum Sententiarum, ordinatio: prologus et distinctio prima , 1967
    • Vol. 2: Scriptum in librum primum Sententiarum, ordinatio: distinctiones II-III , 1970
    • Vol. 3: Scriptum in librum primum Sententiarum, ordinatio: distinctiones IV-XVIII , 1977
    • Vol. 4: Scriptum in librum primum Sententiarum, ordinatio: distinctiones XIX-XLVIII , 1979
    • Vol. 5: Quaestiones in librum secundum Sententiarum (Reportatio) , 1981
    • Vol. 6: Quaestiones in librum tertium Sententiarum (Reportatio) , 1982
    • Vol. 7: Quaestiones in librum quartum Sententiarum (Reportatio) , 1984
    • Vol. 8: Quaestiones variae , 1984
    • Vol. 9: Quodlibeta septem , 1980
    • Vol. 10: Tractatus de quantitate et tractatus de corpore Christi , 1986


  • Wilhelm von Ockham: Texts on the theory of knowledge and science , translated by Ruedi Imbach , Stuttgart 1984 (Latin texts and German translations)
  • William of Ockham: Philosophical Writings. A Selection , ed. Philotheus Boehner, 2nd, revised edition, Indianapolis 1990 (Latin texts and English translations)
  • Guillaume d'Occam: Commentaire sur le Livre des prédicables de Porphyre, précédé du proême du Commentaire sur les Livres de l'art logique , trans. by Roland Galibois, Center d'Études de la Renaissance, Sherbrooke 1978. ISBN 0-88840-655-X
  • Wilhelm von Ockham: De connexione virtutum. About the connection of the virtues , trans. by Volker Leppin, Herder, Freiburg i.Br. 2008. ISBN 978-3-451-28711-4 (Latin text of the Quaestio de connexione virtutum based on the edition in Opera theologica vol. 7 and German translation)
  • Wilhelm von Ockham: Dialogus. Excerpts from political theory , trans. by Jürgen Miethke, Wissenschaftliche Buchgesellschaft, Darmstadt 1992. ISBN 3-534-11871-5
  • William of Ockham: Quodlibetal Questions. Volumes 1 and 2, Quodlibets 1–7 , trans. by Alfred J. Freddoso and Francis E. Kelley, Yale University Press, New Haven 1991. ISBN 0-300-07506-5 (as paperback two volumes in one)
  • Wilhelm von Ockham: sum of logic. From Part I: About the Terms , translated by Peter Kunze, Meiner, Hamburg 1984, ISBN 3-7873-0606-4 (Latin text and German translation)
  • Ockham's Theory of Terms. Part I of the Summa Logicae , trans. by Michael J. Loux, University of Notre Dame Press, Notre Dame (Indiana) 1974. ISBN 0-268-00550-8
  • Ockham's Theory of Propositions. Part II of the Summa Logicae , trans. by Alfred J. Freddoso and Henry Schuurman, University of Notre Dame Press, Notre Dame (Indiana) 1980. ISBN 0-268-01495-7
  • Demonstration and Scientific Knowledge in William of Ockham. A Translation of Summa Logicae III – II: De Syllogismo Demonstrativo, and Selections from the Prologue to the Ordinatio , trans. by John Lee Longeway, University of Notre Dame Press, Notre Dame (Indiana) 2007. ISBN 978-0-268-03378-1
  • Wilhelm von Ockham: Brief summary of Aristotle's books on natural philosophy (Summulae in libros physicorum) , trans. Hans-Ulrich Wöhler, deb Verlag, Berlin 1987. ISBN 3-88436-519-3


  • Jan P. Beckmann (Ed.): Ockham Bibliography 1900–1990 , Felix Meiner, Hamburg 1992, ISBN 3-7873-1103-3
  • Léon Baudry: Lexique philosophique de Guillaume d'Ockham , Lethielleux, Paris 1958

Web links

Commons : Wilhelm von Ockham  - Collection of images, videos and audio files
Work editions


  1. Leppin (2003) pp. 119-122; Beckmann (1995) pp. 20f .; Miethke (1969) pp. 29-34. Miethke points out that Ockham was able to function as a master's degree in a religious study, although he had not obtained that degree at Oxford.
  2. On Ockham's youth, training and early teaching activities, see Beckmann (1995) pp. 19–21; Leppin (2003) pp. 5-25, 33-41, 87-90; Miethke (1969) pp. 1-14.
  3. Miethke (1969) pp. 51–54.
  4. Miethke (1969) p. 65.
  5. On Ockham's stay in Avignon, see Beckmann (1995) pp. 21–23; Leppin (2003) pp. 105-111, 119-139; Miethke (1969) pp. 46-74.
  6. Miethke (1969) p. 106f.
  7. Leppin (2003) pp. 270f.
  8. Gedeon Gál: William of Ockham Died Impenitent in April 1347 , in: Franciscan Studies 42 (1982) pp. 90-95; Leppin (2003) pp. 268-270.
  9. Beckmann (1995) pp. 36-40.
  10. Beckmann (1995) pp. 40-42.
  11. Hubert Schröcker: The relationship between God's omnipotence and the contradiction principle according to Wilhelm von Ockham , Berlin 2003, pp. 85–87, 140f.
  12. ^ Frustra fit per plura, quod fieri potest per pauciora (Ockham, Summa logicae 1,12); Beckmann (1990) p. 203 note 3 has compiled further passages.
  13. Pluralitas non est ponenda sine necessitate (Ockham, Scriptum in primum librum sententiarum , Prologus , Quaestio 1 , in: Ockham, Opera theologica , volume 1, p. 74); Beckmann (1990) p. 203 note 4 has compiled further passages. See also Leppin (2003) pp. 62f.
  14. Leppin (2003) p. 63.
  15. Miethke (1969) p. 238.
  16. Aristotle: Physics 187b10-13, 188a17f., 189a11-20. Ockham: Expositio in libros physicorum Aristotelis 1,11,9, in: Ockham, Opera philosophica , Volume 4, p. 118.
  17. Jan P. Beckmann: Ontological principle or methodological maxim? Ockham and the economic thought then and now , in: Wilhelm Vossenkuhl and Rolf Schönberger (eds.): Die Gegenwart Ockhams , Weinheim 1990, pp. 191–207, here: 191 and 203.
  18. Beckmann (1995) p. 53f.
  19. Ockham, Summa logicae 2.32-33; see Philotheus Boehner: Medieval Logic , Chicago 1952, p. 67f.
  20. Gabbay, Reynolds, Finger: Temporal Logic , pp. 66-68
  21. ^ Ockham, Breviloquium de principatu tyrannico 2,3.
  22. Miethke (1969) pp. 288-299.
  23. Ockham: Dialogus 1, 6.99-100 and 1, 7, 47. Gordon Leff / Volker Leppin: Article Ockham , in: Theologische Realenzyklopädie Vol. 25 (1995) p. 15.
  24. Leppin (2003) p. 280.
  25. Leppin (2003) p. 286.