Mental powers and the soul in Kant’s Subjective Deduction and the Second Paralogism

Abstract

Kant’s claim in the Subjective Deduction that we have multiple fundamental mental powers appears to be susceptible to some a priori metaphysical arguments made against multiple fundamental mental powers by Christian Wolff who held that these powers would violate the unity of thought and entail that the soul is an extended composite. I argue, however, that in the Second Paralogism and his lectures on metaphysics, Kant provides arguments that overcome these objections by showing that it is possible that a composite could ground the unity of thought, that properties are powers and therefore the soul could possess multiple powers, and the soul is a thing in itself so it cannot be an extended composite. These arguments lend additional support to the attribution of multiple mental powers to us in the Subjective Deduction.

Keywords:

• Kant
• rationalism
• German Philosophy
• Wolff
• soul
• metaphysics

Acknowledgments

I am grateful to Rachel Zuckert, Rolf-Peter Horstmann, Corey Dyck, Karl Schafer, Colin McLear, Tobias Rosefeldt and the participants in his Colloquium for Classical German Philosophy at Humboldt-Universität zu Berlin, and two anonymous referees for the Canadian Journal of Philosophy for their helpful comments on previous versions of this paper.

Notes

1. All Kant references are to Kant 1900. The Critique of Pure Reason is cited according to the standard A/B edition and page number, and other works are cited according to volume and page (e.g. AA x:xx). Unless otherwise noted, translations are from Kant (1992, 1997, 1998, 2002).

2. Corey W. Dyck has also taken up Kant’s discussion of a fundamental power arguing that faculty psychology is central to the Subjective Deduction and showing that Kant argues for the existence of multiple irreducible mental powers (Dyck 2008). Dieter Henrich also provides an account of the legacy of discussions of a fundamental power that Kant inherits form his German predecessors (Henrich 1994).

3. For discussions of a fundamental power, see Kant (A 648/B 676–A 651/B 679; A 682/B 710–A 684/B 712; A 631ff./B 659ff; A 771/B 799).

4. This reading of aspects of the Second Paralogism is admittedly at odds with how the Second Paralogism is commonly read. On a commonly accepted reading of the Second Paralogism, Kant criticizes an unnamed rationalist for mistakenly concluding that the soul is simple on the basis of a flawed syllogism involving an ambiguous middle term. Kant argues against the rationalist that we have no epistemic justification for inferring that the soul is simple on the basis of formal features of the unity of apperception and therefore the conclusion that the soul is simple is unwarranted. For some influential interpretations, see, for example, Grier (1993), Proops (2010), Kitcher (1982), Bird (2000). I do not intend to disagree with this common interpretation but only to accent the relevance of the arguments for the discussion of a fundamental power of the soul.

5. The claim that Kant maintains that spatial properties apply only to appearances and not things in themselves is controversial and rests on a metaphysical interpretation of Kant’s transcendental idealism. Given constraints of space, I do not argue for such an interpretation here. However, there is ample evidence for this interpretation, and it has been well defended in the secondary literature. For a concise overview of contemporary interpretations of transcendental idealism, see Schulting (2011). For the most recent defense of a metaphysical interpretation of Kant’s transcendental idealism, see Allais (2015).

6. See Baumgarten (1757, §745–747, §756, §757) for discussion of the soul.

7. See Wolff ([1720] 1751). Translations of Wolff and Crusius are from Watkins (2009). Translations that do not appear in Watkins’ text are my own.

8. On Wolff, Deutsche Metaphysik §728, §730, §735–736, see Kant’s Transcendental Deduction (A 84–A 130/B116–B169).

9. On Wolff’s conception of the soul, see Blackwell (1961).

10. A simple thing in contrast is something that does not have parts: ‘Since whatever has parts is called a composite thing, one conversely calls whatever does not have parts a simple thing’ (Wolff [1720] 1751, §75). Such simple things must exist as the ground of composite things otherwise we would have an infinite regress, which would violate the principle of sufficient reason (§76).

11. Watkins’ interpretation also agrees that extended composites arise from the aggregation of simple substances (Watkins 2006, 284–289). For a similar argument for how simples constitute extended composites, see Wolff (1763, §548). Wolff also maintains in Ontologia that the essence of a composite consists in its accidents and that such accidents must be grounded in substances (Wolff 1763, §789, 791). This means that the accident of extension that is attributed to a composite is grounded in the accidents of the individual substances that constitute the composite. Extension, in other words, is grounded in the distinctness and externality of the simple substances that constitute extended composites.

12. See also Wolff (1737, §216).

13. Wolff is also skeptical in Psychologia rationalis about how one would conceive of the interaction of multiple powers in a single substance; see Wolff (1734, §57).

14. Crusius writes: ‘[I]f a finite thing is supposed to be capable of more than one kind of action, then its fundamental essence must consist in more than one power, [in] which [case these powers] are combined according to certain laws of action among each other. There is also nothing absurd in combining several fundamental powers into a single one, even in a simple subject, as long as one does not represent the powers as something corporeal, but rather notices that uncountably many of them can be combined in a single subject, which do not subsist in different spaces, but rather in a completely identical point of the subject, and which completely penetrate it if it is simple’ (Crusius [1745] 1766, §73).

15. Crusius discusses spirits as simple substances (Crusius [1745] 1766, §473) and simples and composites (Crusius [1745] 1766, §103–119).

16. See, for example, Metaphysik L₁ (AA 28:261–262) and the passages mentioned below.

17. Unlike Wolff, who makes a strict distinction between a faculty (Vermögen) and a power (Kraft), Kant does not adhere closely to this distinction. Thus, he alternately refers to a capacity to judge (Vermögen zu urteilen) (A 69/B 94), or equivalently a capacity to think (Vermögen zu denken) (A 81/B 106), and the power of judgment (Urteilskraft) (A 136/B 175). However, Kant was well aware of Wolff’s distinction, and it appears likely that he would not have objected to the idea that a power is needed in order for a faculty to be exercised. In Metaphysik Volckmann Kant writes for example: ‘Capacity [Vermögen] and power [Kraft] must be distinguished. In capacity we represent to ourselves the possibility of an action, it does not contain the sufficient reason of the action, which is power [Kraft], but only its possibility’ (AA 28:434). See also Metaphysik Mrongovius (AA 29:822ff.) and Metaphysik L₂ (AA 28:565) for Kant’s discussion of Wolff’s distinction between faculty and power. Beatrice Longuenesse also suggests that Kant is sometimes but not always strict in making this distinction in the Critique of Pure Reason (Longuenesse 1998, 7–8).

18. See Dyck (2008) for such an argument.

19. For a discussion of the powers of the soul see Wuerth (2014). Wuerth identifies three such powers (which he refers to as faculties): the faculty of cognition, faculty of desire, and faculty of pleasure and displeasure.

20. There is of course a tradition of Kant interpretation that attempts to do away with the vestiges of Kant’s discussion of the soul and faculty psychology in favor of uncovering the analytic argument of the Transcendental Deduction. See, for example, Strawson (1966). However, it is unclear how such an account can make sense of Kant’s moral philosophy where the postulate of the existence of a substantial soul plays a central role in making sense of the pursuit of the highest good.

21. Although it is clear that Kant rejects rationalist arguments for the substantiality of the soul in the First Paralogism, in his practical philosophy he argues that there is reason to think that we are a substantial soul. And although Kant does entertain the idea that the unity of thought does not tell me ‘whether I could exist and be thought of only as subject and not as predicate of another thing’ (B 149), i.e. that I could be an accident of some substance in Spinoza’s sense, his practical philosophy makes it clear that this is not his positive view. On the substantial soul in Kant’s practical philosophy, see Tester (2016).

22. For a discussion of Kant’s changing positions about the soul as a substance in the A and B editions of the Critique of Pure Reason, see Horstmann (1993).

23. Commentators disagree about the relevance of the Transcendental Deduction for the Paralogisms; for opposing views, see Kitcher (1982) and Grier (2001, 167).

24. On the distinction between external and internal effects, see Wunderlich (2001, 180).

25. Earlier discussions of the verse argument can be found in Metaphysik Herder (AA 28:44). See also Dreams of a Spirit–Seer (AA 2:322, AA 2:328n). Knutzen provides such a verse argument in Knutzen (1744, §7–8).

26. Julian Wuerth has provided an interpretation according to which we could make a legitimate synthetic a priori claim that we are a simple substance. On his interpretation, Kant believed we are aware of ourselves in immediate self-consciousness as a simple substance devoid of predicates but with certain attributes and powers. He also recognizes, however, that Kant is explicitly rejecting any awareness of or epistemic access to the soul as a simple substance in the way the rationalist discusses this substance, i.e. as persisting or as not being spatially composite, since the conditions for the application of this concept of substance are missing in our immediate awareness of ourselves (Wuerth 2016, 174–181). Although it is clear that Kant maintained this position in the 1770s, there is less evidence for it in the Critique of Pure Reason; by then, it appears Kant had already begun to develop an argument for the simplicity of the soul, which maintains that it must be presupposed for moral purposes; see Tester (2016).

27. This is not the only way to understand how synthetic a priori claims could be justified. Colin Marshall has argued that for Kant some synthetic a priori claims about representation-independent objects can be explained on the basis of certain explanatorily basic synthetic a priori claims about the mind. And Kant is justified in making these explanatorily basic claims about the mind on the basis of a reflective and abstractive method that yields knowledge of the formal features of the mind, but not cognition of the mind itself. But he also recognizes that the kind of rational reflection he points out cannot deliver knowledge about the features of the soul discussed in rational psychology such as simplicity and identity. The formal features of the mind determine nothing about the nature of the thinking subject (Marshall 2014, 549–576). However, it seems that some of the most important synthetic a priori claims Kant makes are those regarding the soul. One place to look to justify such claims is not reflection on the mind itself but reflection on the necessary conditions for morality as Kant does in the Critique of Practical Reason.

28. It might be thought that Wolff could maintain that although it is logically possible that a composite of substances grounds the unity of thought, it is not possible in reality. However, Wolff does not distinguish between logical and real possibility. For Wolff, anything that is non-contradictory is possible in reality and anything that is contradictory is not possible in reality. See Wolff ([1720] 1751, §12). So given Wolff’s conflation of logical and real possibility, Kant’s argument can be taken to apply to both the logical and real possibility of a composite of substances grounding the unity of thought. Of course, Kant distinguishes between logical and real possibility and argues that the former does not entail the latter, but this distinction does not affect the argument here against the rationalist.

29. Marshall argues Kant may have held an ‘effect-relative view of the self’ according to which the self is constituted by whatever thing or things are causally responsible for the unity of experience. Although he is right that such a view is a possibility for Kant and that such passages provide evidence for this interpretation, it is ultimately clear that in his practical philosophy Kant maintains that we have to posit a simple, substantial soul as the ground of thought; see Tester (2016).

30. Several metaphysically rich options for understanding the causal relation between noumenal substances and empirical thoughts have been proposed. See, for example, Watkins (2004) and Ertl (1998).

31. For similar thoughts on the predicates of inner and outer sense, see Kant, R 4673 (AA 17:368); R 5059 (AA 18:75).

32. This does not mean, however, that Kant thinks that things in themselves could not be composite simpliciter. It only means that they could not be extended, spatial composites.

33. For Kant’s other discussions of the number of powers and our knowledge of fundamental powers, see: Metaphysik L₁ (AA 28:261f., AA 28:431, AA 28:432, AA 29:770), and R 4825 (AA 17:739). Kant does sometimes seem to believe that the soul can have only one Grundkraft; see Metaphysik L₁ (AA 28:210, AA 28:261). Kant also sometimes appears suspicious of Crusius’ proliferation of the powers of the soul, as in the Logik Blomberg (AA 24:82).

34. A reviewer has pointed out that it might be wondered whether Kant could maintain that the unknown root of the mental powers of the soul could be some other power, for example, a power of nature or some power inherent in God. Kant does not rule this out, and indeed it is consistent with A 15/B 29. However, one problem with thinking that Kant would maintain this is that his account of freedom requires that our power of reason be independent, and it is unclear whether this could be the case if reason as a power were merely the effect of some other fundamental power. There is also a great deal that would need to be said about the relationship between fundamental mental powers and powers in nature. For a discussion in this direction, see Ameriks (2000, 246). Ameriks points out that in the Metaphysical Foundations of Natural Science, Kant actually posits two fundamental forces or powers of nature, attraction and repulsion, but this does not determine whether mentality may be reducible to a single fundamental power. Crusius also suggests that there may be a ‘true and single fundamental power’ in God. This is, however, an infinite power, which does not have a single proximate action and has to be distinguished from the fundamental powers of finite creatures (Crusius [1745] 1766, §73).

35. For the beginnings of such an approach, see Tester (2016).