Karin Nisenbaum's book For the Love of Metaphysics is a densely scrupulous and original piece of scholarship that casts new light on both the development of German idealism and its aftermath in the work of Franz Rosenzweig.1 It is also a powerful argument in support of what she calls the love of metaphysics, understood as the discipline of grounding and guiding the exercise of practical reason in life, in its role of determining genuinely available, arguably non-optional ends the pursuit of which is fully satisfying for reflective beings. In short: the reader is offered a new story about the trajectory of idealism and a new picture of fully meaningful human life and the place of metaphysical thinking in it.

The connection between these two lines of thought is, of course, that the main figures whom Nisenbaum treats—Friedrich Heinrich Jacobi, Salomon Maimon, Immanuel Kant, F. W. J. Schelling, and Rosenzweig—were themselves passionately engaged with the nature of pure reason, especially pure practical reason, and its potential apt expression in human cultural life in credible and exemplary ways. "Jacobi and Fichte," she writes, and we can add Kant and Schelling and Rosenzweig, "can still help us to understand the place of freedom and the role of commitment within philosophical reflection" (LM 14). At its most general level, as Nisenbaum puts it,

the project of German idealism [is] the attempt to meet the demand for a comprehensive, rational explanation of all aspects of human experience, [LM 14]

including especially its subject/object structure and humans' reflective awareness, "without falling prey to nihilism" (LM 14). At stake in this effort is more than simply theoretical knowledge of the place of reflectively accessible representation of objects in the natural world, but also whatever it is that enabled Rosenzweig "to affirm the value of the world and of human action in the world" (LM 15).

Reacting against Kant and Spinoza, Jacobi raises this issue sharply. In place of fundamental, critical explanations of theoretical and practical reason that refer to first principles, he urges trust in common reason and pre-reflective experience that, he thinks, give access to both ordinary objects and God. Achieving this trust requires, notoriously, a salto mortale, but that dangerous leap is neither unmotivated nor unreliable, albeit that it is without exterior ground. Jacobi's account of it resembles Kant's account of one's belief in God as matter of practically necessitated rational faith rather than as a matter of theoretical proof. The exercise of theoretical reflective reason alone, involving tracing series of conditions, yields only skepticism regarding ultimate grounds and nihilism regarding whether conditioned events have any meaning or value.

Maimon finds Kant's argument incomplete in respect of its failing to provide any explanation of why the transcendental unity of apperception, the forms of intuition, and the forms of judgment are given as they are. Maimon undertakes to remedy this defect by arguing that the unity of apperception, space and time, and the Kantian categories are necessary conditions for the comparison and differentiation of any object of thought or for forming any representation of an object. Living up so far as one can to the demand to think any object fully, in all its relations to all other objects, amounts to approximating, so far as humans can, the standpoint of God as "infinite intellect that creates all objects in the act of knowing them" (LM 98). Since one cannot do this completely, however, in so far as human standpoints remain finite and conditioned by the categories and the forms of intuition, one cannot fully ground the suggested account of the unity of apperception, the forms of intuition, and the categories in knowledge of an object. Hence Maimon is both a rational dogmatist in positing a divine intellect that conditions all things and an empirical skeptic in holding that no decisive reason supports this posit. One can take a divine standpoint of complete knowledge to exist, but one can never fully occupy it nor can anyone genuinely know that it is available. The claim that finite intellect in human beings is conditioned by and can partially approximate an infinite intellect remains for Maimon, in Nisenbaum's assessment, an assumption with "the epistemic status...of a hypothesis" (LM 101).

Fichte's account of Tathandlung as an original, non-reflective activity through which humans posit themselves, both theoretically as finite subjects who are aware of finite objects and practically as capable of freedom and bound by the moral law, is modeled on Kant's account in the Critique of Practical Reason of a man enjoined to give false testimony under pain of death. Kant's idea is that any reflective subject of a suitable age is capable of recognizing the possibility of resisting an injunction to false testimony, even if one in fact turns out to succumb to it. Nisenbaum refers to a study by Sergio Tenenbaum in order to substantiate her claim that "Kant's example can be regarded as an invitation to ‘have as an ideal pure self-determination'" (LM 140),2 coupled with the thought that one is capable of freely committing oneself to this ideal. According to Fichte, the recognition by humans of Tathandlung as original activity in us and of the demands it makes on us works in the same way. One is simultaneously to acknowledge the availability of an ideal of free activity and to commit oneself to living up to it. Nisenbaum supports her parallel between Fichte's considerations regarding a principle of consciousness and her account of acknowledging the Kantian moral law (LM 142) by quoting a passage from Fichte's Review of Aenesidemus in order to suggest that the moral law

does not have to express a fact just as content [eine Tatsache, actual fact]; it can also express a fact as performance [eine Tathandlung, actual deed].3

In a motif that will prove central to Nisenbaum's own overall view, self-understanding of oneself as a finite, reflective, representing subject bound by the moral law is a function of commitment in responding to a summons rather than of knowledge regarding any object, finite or infinite (LM 145).

Nisenbaum reads Kant as undertaking to exhibit practical life within nature and within space and time as fully rationally affirmable primarily in his three postulates of pure practical reason, according to which, by accepting the rationality of belief in God, humans are able coherently able to hope and work for a world in which virtue is crowned with happiness. In reading both the transcendental deduction in Kant's Critique of Pure Reason and the argument for the rationality of belief in God as developed in Kant's Critique of Practical Reason, Nisenbaum emphasizes what she calls "the performative and first-personal aspect of transcendental arguments" (LM 111). In the case of the Critique of Pure Reason, this emphasis leads Nisenbaum to treat the transcendental deduction of the categories as moving from the premise that the categories of reasoning apply to all sensible intuitions to the conclusions (a) that they apply to all possible sensible intuitions, and (b) that the synthesis of intuitions in general is an element of a teleological activity that aims at displaying the complete unity of experience: as she puts it,

we only determine our representations and bring them under concepts insofar as we have in view the complete unity of these representations. [LM 68]

This aim is not fully achievable, but it is also non-optional; commitment to it is built into the structure of our cognition. In the Critique of Practical Reason, along the lines of the gallows-false testimony case, Nisenbaum finds acceptance of both the fact of freedom and the reciprocal implication between freedom and obligation to be acts that any human being is able to carry out. This means that one's commitment, in the form of acknowledging or accepting one's capacity for self-determination under the moral law is, again, more crucial than having theoretical knowledge for the purpose of achieving orientation in life.

Schelling offers a yet thicker account of how free and meaningful life in nature is possible by developing a teleological account of natural beings, drawing on Kant's regulative teleology in the Critique of Judgment. All things are capable of autonomy, understood in Nisenbaum's words as "development in accordance with one's own rational nature" (LM 182). But this teleological metaphysics does not yet capture the distinctiveness of human life and experience; in particular, it does not account for the human power of choice in shaping one's life independently and for the ensuing possibility of evil. Schelling then faces the problem of explaining how "the human person individuates herself" (LM 191) both as distinct from other animals and as a distinct individual personality, through either a defiant turn to evil or through loving the good, while also remaining a product of divine and presumably good creation. Nisenbaum argues that for Schelling the solution to this problem is to see God as originally inchoate and incomplete (LM 193), in embodying both an "anarchic, negating force" and a "rational, self-giving force" (LM 196). In an echo of Aristotle's Metaphysics, Book XII, God must, as it were, somehow come in time to will continuously a form of self-actualization that is complete, self-sustaining, and good. In this scenario, the human being, as ectype, in learning to will the good over time on the model of God, the archetype, "is the vehicle for the self-disclosure of the Absolute" in and through its forming of commitments and its testing of them for rationality (LM 204).

Rosenzweig takes up the central project of the German Idealist tradition of both explaining all human experience, including the subject-object relation, and presenting human life as worthy of affirmation through the achievement of properly oriented willing, but he puts a yet stronger religious and communitarian spin on it: Reflective thought is possible only in community with others. Furthermore, value is open to being immediately perceived, as in Jacobi and in Nisenbaum's reading of Kant's gallows-false testimony case, yet only within relations of shared commitment. Hence, humans gain the required orientation through shared responsiveness to the revealed word of God, which awakens them to personhood and love of the neighbor (LM 220). Trust and openness to transformation, in response both to the word and to others, are crucial (LM 225). According to Rosenzweig, perfectionist movement from empty formal freedom, to particularity and defiance, and at last into joint responsiveness to God's summons and love is possible. Were this to occur, God would be himself redeemed from any specific name and any merely particular community.

Focusing on her chosen central themes of the explanation of experience, the priority of practical reason, and the effort to present human cultural life as affirmable, Nisenbaum tells a compelling story. Her emphases highlight the passionate, existential, and temporally and culturally situated dimensions of metaphysical thinking, casting it as a form both of love and pursuit of the good, as well as potentially a significant contribution to their achievement. German idealism is not merely, or primarily, about correct theoretical representation. It is an expression of and response to the eros of self-conscious and reflective beings who are attempting to find and make meaning. Her story fully realizes her primary ambition of casting a new light on the development of German Idealism in a way that makes its central figures attractive and passionately human.

At a more particular level, I was especially impressed by Nisenbaum's uncovering of Maimon's use of the term "the Notion" to describe the active divine intellect—for Maimon only a hypothesis—that is embarked on a course of self-actualization (LM 104). Her account of the broad idea in Kant, echoing work by Onora O'Neill among others, that reason, and ultimately practical reason, is always already at work in establishing the structure of discursive consciousness under the categories, and, further, that that work of reason remains to be completed in constructive worldly practice, is exemplary for this. As Kant famously puts it in the Groundwork,

there can, in the end, be only one and the same reason, which must be distinguished merely in its application.4

For the Love of Metaphysics itself displays the very combination of commitment to argumentative explanation and passionate concern for praxis that is manifest in its central philosophical figures.

While I share Nisenbaum's commitments and I have been instructed by both her scholarship and her passion, I nevertheless also want to raise four questions about her argument. The first three are on specific points of scholarship; the fourth (hinted at by the second and third) is methodological and meta-philosophical in very broad terms.

(1) Following Dieter Henrich and Karl Ameriks, Nisenbaum reads the transcendental deduction in the Critique of Pure Reason as a regressive argument moving from the premise that the categories apply to (or play a role in structuring) all sensible intuitions to the intermediate step that the categories apply to all intentional contents to the modal conclusion that it is not possible for one "to describe matters of fact without already employing a priori laws" (LM 74). I have no doubt that Kant thinks each of these ideas, but can this be the conclusion of the argument as well? It sounds like an answer to the quid facti: humans do in fact thus represent objects to themselves and describe matters of fact as states of affairs involving substances and their alterations under causal laws. We are compelled to do this. But it seems not to answer the quid juris—namely, are we entitled to do this? Does empirical nature really consist of a quantum of substance, of particulars which always undergo alterations in accordance with a causal law? That corresponds to the Humean question that awoke Kant from his dogmatic slumbers, and I do not see that the Transcendental Deduction, as Nisenbaum understands it, even begins to supply an answer to it.

There are, of course, mountains of commentaries on this issue. My own reading broadly follows those of Paul Guyer, Arthur Melnick, and Robert Paul Wolff, among others. I agree that the premise of the Transcendental Deduction can be taken as either "I have discursively structured or judgmental experience; I make judgments" or "My consciousness is apperceptively unified." These two claims reciprocally imply each other, and both are true, on my reading of Kant, in virtue of reason's stimulation of the understanding. But the task of the deduction is then to get from these premises to the first and second Analogies of Experience.

(2) I am puzzled by Nisenbaum's claim, following Michelle Kosch, that according to Kant "evil is unintelligible" (LM 190n60, citing Kosch) and that Kant "fails to account for the possibility of evil as a positive capacity" (LM 186). This claim lies behind Nisenbaum's turn to the later Schelling and Rosenzweig as offering better accounts of evil as consisting in defiance of one's likeness to the formed, positive, loving aspect of God. I am not sure I see the difference here. Admittedly, it is true that in The Metaphysics of Morals Kant writes that

freedom of choice cannot be defined—as some have tried to define it—as the ability to make a choice for or against the law...even though choice as a phenomenon provides frequent examples of this in experience.5

But I take this to be a claim not to the effect that one cannot choose evil, but instead I interpret this to mean that making such a choice—something of which there are frequent examples in experience—is not the telos of the power of choice or Willkür. It is not what choice is for. In Kant's Religion within the Boundaries of Mere Reason—and Nisenbaum cites many of its relevant passages—one's self-centered choice to do evil is a matter of failing to use the power of choice as it ought to be used, according to its proper nature, but instead setting the material incentives of self-preservation and self-love above "a predisposition to [moral] personality."6 Kant titles Part III of the Religion:

Concerning the victory of the good over the evil principle and the founding of a Kingdom of God on earth [RB 66],

with the aim of sketching an account of how human beings over time may learn to understand the proper telos of willing more fully and subsequently to achieve a better willing regarding matters of concrete worldly practice, through the development and eventual ultimate secularization of religious institutions.

If this interpretation is correct, then Kant does have an explanation of evil that is not so far from the defiance-of-God explanation that is present in Schelling and Rosenzweig, with the qualification that religious practice under the control of established institutions is not central to the ultimate achievement of free and meaningful life. I wonder what Nisenbaum makes of this possibility and I will return to this point in my final question below.

(3) G. W. F. Hegel is certainly a more theoretically and institutionally oriented thinker than Maimon, Jacobi, Schelling, Rosenzweig, and Fichte are. Reasonably enough, Nisenbaum omits Hegel from her story on the grounds that for Hegel the Absolute is fully rationally cognizable and that it is topic of theoretical rather than practical philosophy (LM 15-6). Yet, is this so? Hegel does hold that philosophy is fully completable and hence not a matter of a continuing, not yet satisfied eros that is expressed in the ongoing development of a metaphysics and practice of practical reason. But that is not to say that practical reason plays no role in his metaphysics. Theoretical philosophy—Hegel's own system—is in the end descriptive of what he takes to be the achievements of practical reason, exercised by human beings understood as vehicles of Spirit, who are at least incipiently constructing a Sittlichkeit of reciprocal recognition or a cultural order of free and meaningful life. Philosophy may neither offer prescriptions to nor gain content from outside that achievement, itself being managed via dialectical interaction between on the ground development of new forms of practical life and reflective thinking about them; sometimes bound up with violent conflict and upheaval. By my lights, there is a passion or eros of practical reason—reason that is both commitment-forming and reflective—that is driving this development. Depending on what one makes of the famous owl of Minerva passage and related closure claims and balanced against some late remarks in Hegel's Aesthetics that modern life remains "burdened with the abstraction of developing solely in the province of thinking,"7 one might even find in Hegel some qualification of pronouncements about the end of history and the final achievement of Absolute Knowledge.

My question for Nisenbaum then is this: might it not be a good idea to take up some of Hegel's explicit economic, political, and institutional thinking, understanding it in humans' own terms as part of the modern, continuing metaphysico-practical eros of reason? If one does not do this—if one does not think institutionally, economically, and politically as well as ethically—then one runs, I think, some risk of falling into a kind of Feuerbachian position that was rightly criticized by Karl Marx and Friedrich Engels. Ludwig Feuerbach famously held that the full expression of the divine nature of humanity itself, where

Man is nothing without God; but also, God is nothing without man,8

is centrally a matter passionate love and charity, of sex and soup-kitchens, as it were. Or as he put it,

The joyful feeling of the giver is only the reflex, the self-consciousness, of the joy in the receiver. Their joy is a common feeling, which accordingly makes itself visible in the union of hand, of lips. [EC 229]

About this viewpoint Engels scathingly remarked,

And here we are again struck by Feuerbach's astonishing poverty when compared with Hegel. The latter's ethics, or doctrine of moral conduct, is the philosophy of right and embraces: (1) abstract right; (2) morality; (3) social ethics (Sittlichkeit), under which again are comprised: the family, civil society and the state. Here the content is as realistic as the form is idealistic. Besides morality the whole sphere of law, economy, politics is here included. With Feuerbach it is just the reverse. In form he is realistic since he takes his start from man; but there is absolutely no mention of the world in which this man lives; hence, this man remains always the same abstract man who occupied the field in the philosophy of religion.9

Perhaps it would be better here to take Hegel, or a modernized Hegel, as a model rather than Feuerbach, Jacobi, Schelling, and Rosenzweig.

(4) My main philosophical-methodological question, already hinted at above, is to wonder whether one should follow Jacobi, Maimon, Fichte, Schelling, and Rosenzweig in their foundationalism. More exactly, I doubt that it is a good idea to seek a single first principle that explains all human experience and orients humans toward the highest good. Nisenbaum is at least strongly attracted by the thought that one should do this. In her conclusion, she writes that

my hope is that Rosenzweig's life, and the trajectory of thought that enabled him to address his most pressing and philosophical and existential concerns [that is, the Kant, Jacobi, Maimon, Schelling trajectory]...may enable each of us to affirm the value of the world and our own action in the world. [LM 256]

I have more than a little sympathy with this thought, and I would not want to deny that each one of us should spend some time, at least sometimes, in reflecting on the nature of the highest good, or of free and meaningful joint life, and on how we might as individuals play a productive role in achieving and sustaining it. But I wonder whether our thinking about this should be oriented only or primarily around a single first principle. When we take up such a turn toward principle in an immediate way, then the result, often enough, has a pronounced metaphysico-religious-existentialist-voluntarist cast. I hear this cast in Nisenbaum's remark that

if we believe that our commitments are the site of reason's revelation—this belief should renew our sense of responsibility toward the values that we endorse in living. [LM 233]

I have more than a little sympathy with this, too, and I would not want to deny either a role for the moral law or for religious traditions within this self-scrutiny of human commitments. But emphasizing those two sources of orientation alone tends, I think, to result in the kind of Feuerbachian stance I described earlier. This, too, has its charms and attractions. But humans might also want a more pluralized, temporalized, anti-foundationalist, and political mode of practical thought—without abandoning either religion or principle.

In an important essay, David Wiggins once wrote that one might best approach the meaning of life, or attempt to construct and find a satisfying place within a free and meaningful social, cultural, political, economic, and epistemic order, by thinking

in both directions, down from point to the human activities which answer to it, and up from activities...to forms of life in which [human beings] by their nature can find point.10

Thinking that is so launched and guided will be critical and provisional. Religious thought and practice and moral principle can play roles within such thinking, alongside with political, artistic, economic, sexual, and familial thought and practice, among others. Systematicity can be aspired to, but in lived reality, commitments are likely to remain always in part incomplete and provisional. Practical thinking is likely to remain messy and multi-dimensional, rather than centrally religio-ethico-existential. I wonder how Karin Nisenbaum might see German Idealism and specifically Rosenzweig in the light of this suggestion.