Byron Williston, Akrasia and the Passions in Descartes, British Journal of the History of Philosophy 7/1, 1999, 33-55.

Akrasia: motivated irrational action.
Cartesian theory of Akrasia:

1. depends on a notion of 'internal finality',
2. examines a condition of motivated irrationality,
3. entails the denial of mental conflict, bzw.: allows us - indeed requires us - to speak of mental conflict in a qualified sense (p. 34).

Zwei Argumente gegen das scholastische Konzept der finality:

1. die Annahme von causae finales ist nicht mehr als Eibildung und nützt nichts,
2. Alles läßt sich auch ohne erklären (p. 34).

Siehe AT III 648-9, VII 442, III 420, II 200, III 694, IV 292.

'internal finality': J. Laporte, Le rationalisme de Descartes, Paris 1945. J. Collins, Descartes' Philosophy of Nature, American Philosophical Quarterly 5, 1971, 80-93. Kennington. Allgemein: Errol E. Harris, Teleology and Teleological Explanation, Journal of Philosophy LVI, 1959.

This kind of finality would seem for Descartes to apply only to humans, that is to minded bodies. This is so because all organized but mindless complexes - animals for example - actually lose their individual identity when subdivided, and are susceptible of indefinite subdivision, while human individuals do not and are not (p. 35).

Drei Ursachen von Fehlverhalten:

1. mechanical defect
2. defective habit
3. motivated irrationality (Akrasia) (p. 40f.).

Neither defects of nature nor defects of habit are manifestations of weakness, properly speaking. In neither case is the agent responsible for her condition (p. 40f.)

Akrasia setzt Wahlmöglichkeit voraus (p. 41). Entscheidend ist die Stellung des Begehrungsvermögens:

Desire is the only passion which is only a mode of the will (p. 44).
Desire laso gives us the power to thwart the natural goodness of the passions (p. 45).

Williston zitiert David Pears, Motivated Irrationality, Oxford 1984, p. 19:

Desire quietly removes the intellectual obstacle to its own fulfillment.

Descartes' Forderung der Einheit der Seele (vgl. Seele) führt ihn dazu, Akrasia als einen Widerspruch von zu verschiedenen Zeiten auftretenden Motiven zu beschreiben (Passion art. 47, Williston p. 49).

Descartes would have us substitute a horizontal model, such that the agent is seen to be in conflict with his own better reasons over time (p. 50).