Acknowledgements -- Abbreviations -- Chapter 1 -- Introduction -- 1.1 Subject matter -- 1.2 Status quaestionis -- 1.3 Periodisation and sources -- 1.3.1 A chronological list of consulted commentaries -- Anonymus Vennebusch (fl. c. 1260) -- Thomas Aquinas (1224-1274) -- Anonymus Giele (fl. c. 1270) -- Anonymus Bazán (fl. c. 1275) -- Anonymus Van Steenberghen (fl. c. 1275) -- John Duns Scotus (1265/66-1308) -- Radulphus Brito (c. 1270-c. 1320) -- Walter Burley (c. 1275-1344) -- John of Jandun (c. 1285-1328) -- John Buridan (c. 1300-c. 1360) -- Nicole Oresme (c. 1320-1382) -- Anonymus Patar (fl. c. 1340-1350) -- 1.4 Orthography, punctuation and translations -- chapter 2 -- Overview -- 2.1 The introduction of the De anima into the Latin West -- 2.2 The soul as perfectio -- 2.2.1 Avicenna's influence -- 2.3 The soul as forma -- 2.3.1 Immortal but not personal: radical Aristotelianism -- 2.3.2 Formality and subsistence combined: Thomas Aquinas -- 2.3.3 A substance, but also a form -- 2.4 Unicity versus plurality of substantial form -- Unicity or plurality: a psychological or a metaphysical question? -- chapter 3 -- Methodological discussions -- 3.1 The scientific status of the scientia de anima -- 3.1.1 Imperceptibility -- 3.1.2 Simplicity -- 3.1.3 Potentiality -- 3.1.4 The study of the soul within natural philosophy -- 3.1.5 Radulphus Brito against John of Jandun -- 3.1.6 An increasing focus on the intellect -- On the natural philosophical study of the intellect -- Summary -- 3.2 The subject matter of the scientia de anima -- 3.2.1 The soul as subject matter -- From a science of things to a science of terms -- 3.2.2 The ensouled body sub ratione animae as subject matter -- 3.2.3 Leaving the subject matter undecided -- 3.2.4 Summary -- 3.3 The epistemic status of the scientia de anima -- 3.3.1 Unproblematic beginnings: Thomas Aquinas.

3.3.2 Certitude and nobility combined: Anonymus Van Steenberghen and Walter Burley -- 3.3.3 Increasing difficulties: Anonymus Bazán, Radulphus Brito and John of Jandun -- 3.3.4 The final stages: John Buridan and Nicole Oresme -- 3.4 Conclusions -- chapter 4 -- The Aristotelian definition of the soul -- 4.1 Aristotle's definition of the soul -- 4.1.1 Thomas Aquinas's views on the matter of the soul -- 4.1.2 The Anonymi -- The soul: matter or form? -- Having life in potency -- Substantial or accidental act? -- 4.2 Fourteenth-century interpretations -- 4.2.1 The substantiality of the soul -- Material characteristics -- Substantiality confirmed -- Definitional dependence on the body -- 4.2.2 The actuality of the body -- 4.3 Can we perceive the identity of accidents? -- 4.3.1 Thomas Aquinas -- 4.3.2 Radulphus Brito -- 4.3.3 John of Jandun -- 4.3.4 John Buridan -- 4.4 Excursus: condemnations and polemics -- 4.5 Conclusions -- Chapter 5 -- Substance, powers and acts -- 5.1 A curious fourteenth-century thought experiment -- 5.2 One soul or multiple souls? -- 5.2.1 John Buridan's arguments against a plurality of souls -- 5.2.2 Nicole Oresme's hesitation -- 5.2.3 Summary -- 5.3 The relation between the soul and its powers -- 5.3.1 Arguments against a real distinction -- The powers as essential parts of the soul -- The powers as specific differences -- Infinite regress -- 5.3.2 Arguments in favor of a real distinction -- Belonging to different categories -- The differences between the powers themselves -- From simplicity to multiplicity -- 5.3.3 Some preliminary conclusions -- 5.3.4 The identification of the soul with its powers -- Intermezzo: William Ockham -- Conclusions -- 5.4 The soul's presence in the body -- 5.4.1 From annulose to perfect animals -- On different types of wholes -- Whether the whole soul is present in each part of the body.

5.4.2 Is the soul extended or not? -- Ambiguous criteria -- 5.4.3 The discussion of the soul's presence after Ockham -- 5.4.4 Is the power of sight really present in the foot? -- 5.4.5 From annulose animals to perfect animals -- Duns Scotus's formae partiales -- Heterogeneity and homogeneity -- 5.5 From animal soul to human soul -- 5.5.1 The intellective soul: material or immaterial? -- The limits of natural philosophy -- 5.6 Epilogue and conclusions -- 5.6.1 The fragile unity of the science of the soul -- chapter 6 -- Final conclusions -- Radulphus Brito and William Ockham -- Methodology and doctrine -- Natural philosophy, metaphysics and theology -- The disruption of the fragile unity of the scientia de anima -- Bibliography -- Manuscripts -- Published sources -- Secondary literature -- Index Codicum Manuscriptorum.