DOI: https://doi.org/10.1007/s11229-025-05134-z
تاريخ النشر: 2025-07-29
كانط حول الأفكار الكيميائية الخاصة
© المؤلف(ون) 2025
الملخص
في الملحق للجدل المتعالي، يقدم كانط عدة أفكار للعقل، مثل الهواء النقي، والماء النقي، والأرض النقية. أطلق على هذه الأفكار اسم “الأفكار الكيميائية الخاصة”، على النقيض من الأفكار الثلاثة العامة المتعالية، وهي: ‘الله’، و’العالم’، و’الروح’. من بين عدد قليل من الباحثين في كانط الذين يدرسونها، هناك وجهة نظر سائدة مفادها أنه يمكننا اكتشاف أمثلة عليها، مثل تلك التي تحت ظروف المختبر. تنكر هذه الوجهة أن الأفكار الكيميائية الخاصة تحتوي على وحدة تتجاوز بشكل دائم حدود التجربة الممكنة، وهو ما يقدمه كانط كميزة للأفكار بشكل عام. وفقًا لهذه الوجهة، تظهر الأفكار الكيميائية الخاصة في الفرضيات العلمية التي يمكن إثباتها. عندما يتم إثبات هذه الفرضيات، يتم تجسيد الأفكار التي تظهر فيها. على النقيض من ذلك، أجادل بأن الأفكار الكيميائية الخاصة لا تظهر في الفرضيات العلمية التي يمكن إثباتها. بدلاً من ذلك، يتم توليدها من خلال ما يسميه كانط “الاستخدام الافتراضي للعقل”، والذي بالنسبة له ليس كيف ننتج فرضيات قابلة للإثبات، بل كيف نقوم بالميتافيزيقا. الأفكار الكيميائية الخاصة الناتجة، أجادل، تُفهم بشكل أفضل على أنها تشير إلى أنواع طبيعية – عموميات تتجاوز بشكل دائم حدود التجربة الممكنة.
1 المقدمة
فكرتان عن السبب
المفهوم إما مفهوم تجريبي أو مفهوم خالص، والمفهوم الخالص، بقدر ما ينشأ فقط من الفهم (وليس من صورة حسية خالصة)، يُسمى نوتيو. المفهوم المكون من النوتيون، الذي يتجاوز إمكانية التجربة، هو فكرة أو مفهوم عقل. (A320/B377)
3 قراءة الفرضية الفيزيائية
نهدف هنا بالضبط إلى اشتقاق حالات فعلية تجريبية من مثل هذه الأسباب المفترضة. هذه الأفكار المفترضة تؤثر على التجريبي، إذًا، إما (إذا كانت غير ناجحة) كفرضيات تم دحضها أو (إذا كانت ناجحة) كتفسيرات أو تصورات تجريبية جديدة.(2017، 102-103)
4 صعوبات مع قراءة الفرضية الفيزيائية
[أفكار العقل] تُفكر فقط بشكل إشكالي، من أجل تأسيس مبادئ تنظيمية للاستخدام المنهجي للفهم في مجال التجربة بالنسبة لها (كخيالات استكشافية). إذا انحرف المرء عن هذا، فإنها مجرد كيانات فكرية، إمكانية وجودها غير قابلة للإثبات، وبالتالي لا يمكن استخدامها لتأسيس تفسير للظهورات الفعلية من خلال فرضية. (A771/B799)
يجب الاعتراف بأنه من الصعب العثور على الأرض النقية، والماء النقي، والهواء النقي، وما إلى ذلك. ومع ذلك، يتطلب الأمر مفاهيم عنها (مفاهيم، فيما يتعلق بنقائها التام، تنشأ فقط في العقل). (A646/B674)
5 الاستخدام الافتراضي للعقل
من بين الأنواع المختلفة من الوحدة وفقًا لمفاهيم الفهم، تنتمي سببية مادة ما، والتي تُسمى “قوة”. للوهلة الأولى، تُظهر المظاهر المختلفة لمادة واحدة ونفسها تنوعًا كبيرًا لدرجة أنه يجب افتراض وجود عدد كبير من القوى بقدر ما توجد آثار، كما في العقل البشري هناك الإحساس، والوعي، والخيال، والذاكرة، والذكاء، والقدرة على التمييز، واللذة، والرغبة، وما إلى ذلك. في البداية، تأمرنا قاعدة منطقية بتقليل هذا التنوع الظاهر قدر الإمكان من خلال اكتشاف الهوية الخفية من خلال المقارنة، ورؤية ما إذا كان الخيال المدمج مع الوعي قد لا يكون ذاكرة، أو ذكاء، أو القدرة على التمييز، أو ربما حتى الفهم والعقل. فكرة القوة الأساسية – على الرغم من أن المنطق لا يحدد على الإطلاق ما إذا كان هناك شيء من هذا القبيل – هي على الأقل المشكلة التي تطرحها تمثيل منهجي لتنوع القوى. المبدأ المنطقي للعقل يطالب بهذه الوحدة بقدر ما هو ممكن تحقيقها، وكلما وُجدت مظاهر أكثر من هذه القوة وتلك القوة متطابقة، زادت احتمالية أنها ليست سوى تعبيرات متنوعة عن واحدة ونفسها
القوة، التي يمكن أن تُسمى (نسبيًا) قوتها الأساسية. (A648/ B676-A649/B677)
6 أفكار كيميائية معينة هي نقية
تجمع الفئات إما مع أوضاع الحساسية أو مع بعضها البعض لتنتج عددًا كبيرًا من المفاهيم المشتقة أ priori [أي، ما يمكن أن يُنسب]، سيكون من المفيد والممتع إلى حد ما، ولكن هنا جهد يمكن الاستغناء عنه، أن نلاحظ ذلك ونقوم بتصنيفه بالكامل قدر الإمكان. (A82/B108)
على الرغم من أن العالم بأسره يتحدث عن النار النقية، الماء النقي، الهواء النقي، إلخ، يجب أن نعترف أنه لا شيء نقي. نرى، لذلك، أننا نمتلك فقط آثارًا فينا نشير من خلالها إلى أنواع المادة وبالنظر إلى الأولى نسمي الأخيرة نقية. يقوم عقلنا بعمل تصنيفات معينة، والتي تسبق التجربة ووفقًا لها نقوم بعد ذلك بتنظيم تجربتنا. (AA XXIX 161)
7 تحتوي الأفكار الكيميائية الخاصة على أنواع طبيعية تتجاوز حدود التجربة الممكنة
8 الخاتمة
References
Baumgarten, A. (2013). Metaphysics. C. Fugate & J. Hymers (Trans.). Bloomsbury.
Bickmann, C. (2002). Zur systematischen Funktion der Kantischen Ideenlehre. In R. Hiltscher & A. Georgi (Eds.), Perpektiven der Transzendentalphilosophie im Anschluß an die Philosophie Kants (pp. 43-79). Freiburg: Alber.
Carrier, M. (1990). Kants Theorie der Materie und ihre Wirkung auf die zeitgenönissische Chemie. KantStudien, 81(2), 170-210.
Cooper, A. (2022). Hypotheses in Kant’s philosophy of science. Studies in history and philosophy of science (online) (pp. 1-9).
de Boer, K. (2020). Kant’s reform of metaphysics: The critique of pure reason reconsidered. Cambridge: Cambridge University Press.
Ellis, B., & Lierse, C. (1994). Dispositional essentialism. Australasian Journal of Philosophy, 72(1), 27-45.
Engelhard, K. (2018). The problem of grounding natural modality in Kant’s account of empirical laws of nature. Studies in History and Philosophy of Science, 71, 24-34.
Frketich, E. (2019). Wolff and Kant on the mathematical method. Kant-Studien, 110(3), 333-356.
Horstmann, R.-P. (1998). Der Anhang zur transzendentalen Dialektik. In G. Mohr & M. Willaschek (Eds.), Immanuel Kant: Kritik der reinen Vernunft (pp. 525-545). Berlin: De Gruyter.
Karasek, J. (2015). Idee. In M. Willaschek, J. Stolzenberg, G. Mohr & S. Bacin (Eds.), Kant-Lexikon (pp. 1114-1116). Berlin: De Gruyter.
Klimmek, N. (2005). Kants System der transzendentalen Ideen. Berlin: De Gruyter.
Krausser, P. (1988). On the Antinomies and the appendix to the dialectic in Kant’s critique and philosophy of science. Synthese, 77(3), 375-401.
Kreines, J. (2008). Kant on the Laws of Nature: Laws, necessitation, and the limitation of our knowledge. European Journal of Philosophy, 17(4), 527-558.
Massimi, M. (2017). Grounds, modality, and nomic necessity in the critical kant. In M. Massimi & A. Breitenbach (Eds.), Kant and the Laws of Nature (pp. 150-170). Cambridge: Cambridge University Press.
Messina, J. (2017). Kant’s necessitation account of laws and the nature of natures. In M. Massimi & A. Breitenbach (Eds.), Kant and the Laws of Nature (pp. 131-149). Cambridge: Cambridge University Press.
McNulty, M. B. (2014). Kant’s philosophy of chemistry. UC Irvine Electronic Theses and Dissertations.
McNulty, M. B. (2015). Rehabilitating the regulative use of reason: Kant on empirical and chemical laws. Studies in History and Philosophy of Science, 54, 1-10.
Meer, R. (2019). Der transzendentale Grundsatz der Vernunft. Berlin: De Gruyter.
Okruhlik, K. (1986). Kant on realism and methodology: Progress beyond Newton? In R. E. Butts (Ed.), Kant’s Philosophy of physical science (pp. 305-329). Dordrecht: Reidel Publishing Co.
Rauscher, F. (2010). The appendix to the dialectic and the Canon of pure reason: The positive role of reason. In P. Guyer (Ed.), The Cambridge companion to Kant’s critique of pure reason (pp. 290-309). Cambridge: Cambridge University Press.
Spagnesi, L. (2022). The idea of god and the empirical investigation of nature in Kant’s critique of pure reason. Kantian Review, 27, 279-297.
Spagnesi, L. (2023). Regulative idealization: A Kantian approach to idealized models. Studies in History and Philosophy of Science, 99, 1-9.
Spagnesi, L. (2024). Natures, ideas, and essentialism in Kant. Synthese, 204, 1-26.
Stang, N. (2016). Kant’s modal metaphysics. Oxford: Oxford University Press.
Stratmann, J. (2022). The end of explanation: Kant on the unconditioned. Philosophy and Phenomenological Research, 105, 507-532.
von Varnbüler, T. (1890). Widerlegung der Kritik der reinen Vernunft. Prague: Hofbuchdruckerei A. Haase.
Watkins, E. (2019). Kant on infima species. In E. Watkins (Ed.), Kant on laws (pp. 212-224). Cambridge: Cambridge University Press.
Willaschek, M. (2018). Kant on the sources of metaphysics: The dialectic of pure reason. Cambridge: Cambridge University Press.
Zuckert, R. (2017). Empirical scientific investigation and the ideas of reason. In M. Massimi & A. Breitenbach (Eds.), Kant and the Laws of Nature (pp. 89-107). Cambridge: Cambridge University Press.
- Elise Frketich
efrketic@purdue.edu
Cornerstone Integrated Liberal Arts, Purdue University, West Lafayette, IN, USA I have modified the translation of this passage, and I explain why in sect. 4. References to Kant’s texts, with the exception of the Critique of Pure Reason, indicate the volume and page number of the Akademie Ausgabe of his Gesammelte Schriften, edited by the Preussische Akademie der Wissenschaften and published by De Gruyter. References to the first Critique cite the standard A (1781) and B (1787) editions, and I use the Guyer and Wood translation. Translations of untranslated texts are mine.
I follow Spagnesi in calling these ideas “particular ideas” (2022, 296). This name is fitting because Kant calls the specific metaphysical sciences, which feature such ideas, the “particular metaphysical sciences” (AA IV 470).
There is extensive research on Kant’s general transcendental ideas of reason. See, e.g., Bickmann (2002), Grier (2004), Klimmek (2005), and Willaschek (2018).
Kant discusses what he calls “physical hypotheses” in the section of the Doctrine of Method in the first Critique called “The discipline of pure reason in hypotheses” (A772/B800-A773/B801). I explain them in sect. 3.
E.g., Carrier (1990), McNulty (2014), and Meer (2019, 234-235). I thank an anonymous reviewer for encouraging me to expand on this point and to characterize it as a strength.
E.g., Kant explains that ideas contain the “unconditioned” (A311/B367), and he describes them as “imaginary focal points” (foci imaginarii) around which cognition is organized (A644/B672).
Scholars who list ‘pure’ and ‘has an extension that is beyond the bounds of possible experience’ as the defining features of ideas in general are Karasek (2015, 1114ff) and Horstmann (1998, 535).
Kant indicates that ideas are pure and have an extension that is beyond the bound of possible experience in the Stufenleiter (A320/B377). However, some Kant scholars question whether these features apply to all species of ideas, especially in the cases of, e.g., practical and aesthetic ideas. Okruhlik likewise states that particular ideas are idealizations of things found in nature . See also: “The ideas of the pure elements are also, like the ideas proper, posited object-representationsrepresentations of purported objects that are to be governed by the laws we hope to find. Importantly, unlike the ideas of reason, however, the objects of these ideas are not necessarily or irrevocably beyond experience” (Zuckert, 2017, 102). For the view that the particular ideas of reason can become empirical concepts if instances of them are discovered in nature, see further Rauscher (2010, 296-297n5). Okruhlik outright denies that particular ideas have an extension that is beyond the bounds of possible experience . See, e.g., Cooper (2022, 7). Cooper uses as an example McNulty’s description of a chemist, who “reduces all the metals to earth, and measures their weight, all the salts to combustibles, and measures their force, and examines water and air as vehicles, measuring their mechanical properties” (2022, 7). However, it is unclear whether McNulty subscribes to the same theory of hypotheses as does Cooper.
Cooper likewise makes this point (2022, 6). Spagnesi likewise emphasizes that, for Kant, ideas cannot be used in physical hypotheses (2023, 5).
See further, e.g., McNulty (2015, 2).
Kant puts this point as follows: “If the imagination is not simply to enthuse but is, under the strict oversight of reason, to invent, something must always first be fully certain and not invented, and that is the possibility of the object itself” (A770/B798). The original German rules out the latter option because the pronoun “die” in the parentheses must refer to the closest noun with the matching gender according to German grammar, and that is “die Begriffe”. It cannot refer to the group of contents listed in the prior sentence, e.g., pure earth and pure water, because there is a suitable noun that is closer to it than this group. Furthermore, it cannot refer to this group via the “davon” in the same sentence because the latter is, in this context, grammatically inseparable from “die Begriffe”, which brings us back to the same result.
See, e.g., Digitales Wörterbuch der deutschen Sprache and Duden. See further (AA IX 92).
See: “When we call something an idea, we are saying a great deal about its object (as of an object of pure understanding), but just for this reason very little about the subject (i.e., in respect of its actuality under empirical conditions), since, as the concept of a maximum, nothing congruent to it can ever be given in concreto.” (A327/B384, translation slightly modified). Note that this is a universal statement about all ideas, not a statement that can be read as applicable only to the general transcendental ideas.
E.g., McNulty provides a convincing argument for the claim that the particular chemical ideas are a priori, i.e., the object of a particular idea must be a priori to explain the possibility of the necessity of empirical laws (2015, 3-7). However, he does not provide one for the claim that they are pure, and ‘a priori’ does not have the same meaning as ‘pure’ for Kant, even if what is a priori is often also pure (e.g., A20/B34). Furthermore, he does not solve the puzzle of how something that must in some sense originate in experience could be pure.
E.g., McNulty provides two arguments for the claim that the objects of particular chemical ideas are beyond the bounds of possible experience. The first builds on the one that I discuss in the previous footnote: the object of a particular idea must be a priori and unconditioned to explain the necessity of empirical laws, and if such an object is a priori and unconditioned, then it must also be beyond the bounds of possible - experience (McNulty, 2015, 3-5). The second is an argument from definition: all ideas are unconditioned (and therefore beyond the bounds of possible experience), particular chemical ideas are ideas, therefore, particular chemical ideas are unconditioned (McNulty, 2015, 5n25). While I find these arguments convincing, Zuckert, e.g., must not have been convinced by the first because her paper that claims the opposite was published after McNulty’s, and she would deny the minor premise of the second because she holds that particular chemical ideas are not ideas properly speaking (2017, 99; 102-103).
To best understand the hypothetical use of reason, it is helpful to consider the contrast that Kant draws between it and what he calls “the apodictic use of reason” (A646/B674). Both are inferential activities, according to him, but they differ with respect to the epistemic status of their premises. In the apodictic use of reason, the major premise is known to be true, and this necessarily and universally so (A646/B674). E.g., we know that the proposition “three non-linear points always lie on a plane” is necessary and universal because, for Kant, we have evidence of its truth in a priori intuition (A732/B761). We can then use this proposition as a major premise in an apodictically certain syllogism. The principle of parsimony is also frequently referred to as Ockham’s Razor. Kant calls the principle of the systematic unity of reason “the parsimony of principles” (A650/B768), and he cites its Latin expression, “entia praeter necessitatem non esse multiplicanda” (“one should not multiply beginnings (principles) without necessity”) (A652/B680). On my interpretation, reason, in its hypothetical use, not only acts in accordance with the principle of parsimony when generating particular ideas, but it also follows what Kant calls the “logical maxim” and “supreme principle” of pure reason, which he introduces at the beginning of the Transcendental Dialectic. The logical maxim states that reason is “to find the unconditioned for conditioned cognitions of the understanding, with which its unity will be completed” (A307/B376). In short, we seek the condition, i.e., cause, for any conditioned thing until we arrive at something that is unconditioned, i.e., uncaused. For a recent discussion of this maxim in the Kant scholarship, one that gives examples of different kinds of conditioning relations, see Spagnesi (2022, 2). The supreme principle states that “we assume that when the conditioned is given, then so is the whole series of conditions subordinated one to the other, which is itself unconditioned, also given (i.e., contained in the object and its connection)” (A307-308/B364). In short, we assume that if the conditioned exists, then so too exists the entire series of conditions. On my interpretation, the two steps in the example in the main text, including when we reduce the relatively fundamental power to a fundamental one, model the logical maxim. When we then posit the existence of this fundamental power, on my interpretation, this example models Kant’s supreme principle. This interpretation is controversial. Many Kant scholars hold that only the three highest ideas are unconditioned. While I think that particular chemical ideas are likewise unconditioned, I cannot argue for this claim here. I thank an anonymous reviewer of Synthese for urging me to include this point.
I thank an anonymous reviewer of Synthese for this pithy description of the hypothetical use of reason. Note that all assertoric (real) and apodictic (necessary) judgements are also possible (problematic), but not all possible judgements are real or necessary. An assertoric judgement must also be evidenced in intuition and an apodictic judgement is determined through the “laws of the understanding” (A75/B101-A76/ B101).
This description allows for another important contrast between apodictic and hypothetical premises, this time regarding the way that they relate to their respective conclusions. An apodictic premise imparts its truth to the conclusions that follow from it. E.g., under the already-seen apodictic premise that “three nonlinear points always lie on a plane”, we can subsume the following minor premise, which we gain from experience: ‘A, B, and C are three non-linear points’. From these two premises we deduce that ‘A, B, and C lie on a plane’, proving the truth of this conclusion with certainty. By contrast, a hypothetical premise does not have any verifiable truth to impart to the conclusions that follow from it. Instead, we can only verify the truth of these conclusions and attempt to impart it to the hypothetical premise. We can see this in the above-cited passage regarding the fundamental power of the human mind when Kant states that “the more appearances of this power and that power are found to be identical, the more probable it becomes that they are nothing but various expressions of one and the same power”. We know that propositions about appearances of various powers of the mind are true thanks to our observations of them. Yet, we do not know the truth of our hypothetical premise, namely, that these appearances are caused by a fundamental power of the mind. However, if more and more true propositions about these appearances can be derived from our hypothesis, then it becomes more probable.
The only kind of real possibility that has been attributed to particular chemical ideas in the Kant scholarship, as far as I am aware, is the kind that I treat in the main text, and I take myself to show that this kind does not hold of particular chemical ideas. However, Nick Stang forcefully argues that Kant employs additional kinds of real possibility in the first Critique, ones that Kant does not explicitly explain. While it is beyond the scope of this paper to investigate whether an additional kind of real possibility could be attributed to particular chemical ideas, this would be an interesting avenue for future research. A promising avenue for proving a higher-order or pure hypothesis is one that draws on what Kant says about the sufficient grounds for a claim in the section of the first Critique called “On having opinions, knowing, and believing”. See further, e.g., Cooper (2022, 8). Some Kant scholars may hold that a predicable cannot be a feature of an idea of reason because there seems to be a contradiction between predicables and ideas, i.e., predicables are derived, and ideas are unconditioned and therefore not derived. However, I hold that there is no contradiction because, first, predicables and ideas are “derived” and “not derived” in two different senses. The derivation of predicables remains on the level of transcendental logic. The derivation itself does not have ontological import, but rather it only serves to complete the non-fundamental aspects of our table of categories. By contrast, the derivations of which ideas of reason stand at the head have ontological import. They aim at tracking real causal relations (see, e.g., Spagnesi, 2024, 5-6). Furthermore, even if both derivations had ontological import, it would still not be contradictory to include predicables in concepts of reason because something can be unconditioned with respect to one conditioning relation and conditioned with respect to another for Kant (see Willaschek, 2018, 87-98; Stratmann, 2022, 512). Finally, my claim that it is non-contradictory to include predicables as features in ideas of reason is verified by Kant himself as he uses a predicable, namely, ‘incorruptible’, as a feature of an idea of reason, namely, the idea of the soul, as I discuss in the main text.
Since Kant lists corruption as a predicable, its negation must also be a predicable (A82/B108).
Kant calls the idea of pure water a “vehicle” at A646/B674. In the Danziger Physik, he equates a vehicle with a “commercium”, which he describes as the interaction between an active and a passive power (AA XXIX 161). Since the context here is a discussion of mechanics, we can best understand this general description of interaction as one of a material instead of an immaterial interaction. Furthermore, Kant usually uses ‘commercium’ to refer to the interaction of substances in space and time (e.g., A214/B261-A215/ B262, AA XXVIII 215, AA XXIX 854, AA XXIX 853, and AA XXIX 868). I thank an anonymous reviewer for pushing me on this point.
Kant lists the powers whose actualizations that pure water enables in the following: “Earths are the onus, the negative matter that do not have a power to dissolve but rather are to be dissolved. In nature, salt and combustible things are the two potentiae that dissolve everything. […] Salts require water as a vehicle in order to act as powers to dissolve” (AA XXIX 161). Kant reiterates these two steps in the Prolegomena: “As was proper, I called them categories, after their ancient name, whereby I reserved for myself to append in full, under the name of predicables, all the concepts derivable from them – whether by connecting them with one another, or with the pure form of appearance (space and time) or its matter, provided the latter is not yet determined empirically (the object of sensation in general) – just as soon as a system of transcendental philosophy should be achieved, on behalf of which I had, at the time, been concerned only with the critique of reason itself” (AA IV 324).
Note that Baumgarten defines ‘ontology’ as “the science of the more general predicates of a being” (2013, §4). This definition excludes his rational cosmology, psychology, and theology. However, Kant must have had Baumgarten’s entire Metaphysics in mind, including these three branches of philosophy, because Baumgarten only introduces pure concepts like ‘immortal’ in his rational psychology (2013, §781), a concept that Kant attributes to ‘soul’ (A345/B403). As we have seen, for Kant, ‘vehicle’ refers to a material substance that enables the interaction between an active and a passive power, one that is subject to the laws of motion. Furthermore, Kant equates a vehicle with what is called a “machine” (e.g., A646/B674 and AA 29:161). Baumgarten includes ‘machine’ in his metaphysics, which he describes as “a composite being in the strict sense that is moveable according to the laws of motion” .
Some Kant scholars might view this conclusion as too hasty. They might think that Kant’s Metaphysical Foundations of Natural Science (henceforth: MFNS) could likewise be a source of predicables because, in it, Kant undertakes an a priori determination of the concept of matter according to the four types of categories (4:476). While we can indeed locate the ‘power to dissolve’ in the section of MFNS that treats Kant’s theory of dynamics, a problem here arises. We are unable to locate the powers proper to the other particular chemical ideas in it. Thus, appeal to MFNS cannot explain the purity of Kant’s particular chemical ideas either. As Kant puts this point, “only an apodictic proof, insofar as it is intuitive, can be called a demonstration. […] Thus only mathematics contains demonstrations” (A734/B762). Only mathematics is capable of apodictically certain demonstrations, for Kant, because we can only know a premise to be necessarily true-which is a condition of the apodictic use of reason (see note 23)-when we exhibit it in a priori intuition as Kant thinks we do with, e.g., such pure mathematical concepts as that of the triangle. By contrast, according to Kant, philosophy is incapable of necessary premises because it is incapable of strict definitions and axioms (A727/B755-A733/B761). For more on the mathematical method, see Frketich (2019).
See, e.g., AA IV 468; 471. For a detailed discussion of the empirical nature of chemistry due to experimentation as well as the scientific context that Kant alters by positing a pure, albeit problematic ground for this empirical science, see Meer (2019, 224-233). For a detailed discussion of particular chemical ideas as the pure ground of empirical chemistry, see McNulty (2015).
The claim that the object of a particular chemical idea is a natural kind is already maintained by several Kant scholars, e.g., Kreines (2008, 540), McNulty (2015, 6n36), and Spagnesi (2024, 8), which provides further support for my view that this object is a universal-not a hypothetical spatiotemporal object that figures in a physical hypothesis-that is beyond the bounds of possible experience.
I follow de Boer in calling these concepts the “concepts of reflection”, and my description of them is indebted to hers (de Boer, 2020, 191-211). - 43 “It is thereby said that the nature of things themselves offers material for the unity of reason” (A652/ B680).
In addition to the principles discussed in note 24, the “principles of reason” refer to the principles of homogeneity, specification, and continuity (A657/B685-A658/B686). The principle of homogeneity guides the production of genera in our system of concepts. The principle of specification ensures that species are generated to be subsumed under each genus. Finally, the principle of continuity of forms requires that there be no gaps between any genus and species. For a detailed account of these principles, as well as how they contribute to systematizing cognitions, see Watkins (2019). See note 41 for further Kant scholars who hold this view.
Kant knew that chemistry was revising its understanding of the nature of chemical elements in the 18th century, even after the publication of . Since the particular ideas of chemical elements are generated to explain certain empirical cognitions, cognitions whose explanatory needs can change with new empirical information, I hold that lower ideas can change or be replaced. E.g., Kant replaces the particular idea of pure air with that of phlogiston in the Danziger Physik (AA XXIX 161; see McNulty, 2014, 92n138). See further Krausser, who describes this process as a feedback cycle between sense data and Kant’s system of reason (1988, 397-389). The changeable nature of particular ideas is compatible with my view that their objects are universals because these universals are mind-dependent schemata that serve to organize cognitions on my interpretation. When one particular idea no longer fits the empirical data, the mind will replace it with one that does, resulting in a new particular idea of a chemical element with a new schema or universal. I thank an anonymous reviewer of Synthese for pushing me to clarify this point.
For more detailed accounts of this claim, see, e.g., Massimi (2017), Messina (2017), and Engelhard (2018).
I agree with Carrier (1990) and McNulty (2015), who also claim that elements bear powers for Kant. While the individual members of the group embody the features of a material substance because they are physical individuals in space and time, the schema-the object of the idea of a pure chemical elementmerely designates these features, just as the features of a concept do. Although Rauscher is a proponent of the received view, we agree that there are many different types of particular ideas, including biological species (2010, 295-296).
I thank an anonymous reviewer of Synthese for encouraging me to characterize this as a strength of my reading and for guiding my discussion of the third Critique. I began this paper during a research stay at the University of California, San Diego, where I had the pleasure of discussing it with Eric Watkins, Clinton Tolley, and their research group. Since then, I have received further invaluable comments from several scholars on multiple drafts, including Dina Emundts, Pat Kain, Karen Koch, Jacqueline Mariña, JP Messina, Chen Yang, Chris Yeomans, and Pavel Reichl. The research for this paper was funded by a short stay abroad grant, awarded by the Flemish Research Council, and a research fellowship at the “Human Abilities” Centre for Advanced Studies in the Humanities in Berlin.
DOI: https://doi.org/10.1007/s11229-025-05134-z
Publication Date: 2025-07-29
Kant on particular chemical ideas
© The Author(s) 2025
Abstract
In the Appendix to the Transcendental Dialectic, Kant introduces several ideas of reason, e.g. those of pure air, pure water, and pure earth. I call these the “particular chemical ideas” in contrast to the three general transcendental ideas, namely, ‘God’, ‘world’, and ‘soul’. Among the few Kant scholars who study them, one predominant view is that we can discover instances of them, e.g., under laboratory conditions. This view denies that particular chemical ideas contain a unity that is permanently beyond the bounds of possible experience, which Kant introduces as a feature of ideas in general. According to this view, particular chemical ideas figure in scientific hypotheses that can be proved. When these hypotheses are proved, the ideas that figure in them are instantiated. By contrast, I argue that the particular chemical ideas do not figure in scientific hypotheses that can be proved. Instead, they are generated by what Kant calls the “hypothetical use of reason”, which is for him not how we produce provable hypotheses, but rather how we do metaphysics. The resulting particular chemical ideas, I argue, are best understood as denoting natural kinds-universals that are permanently beyond the bounds of possible experience.
1 Introduction
2 Ideas of reason
A concept is either an empirical or a pure concept, and the pure concept, insofar as it has its origin solely in the understanding (not in a pure image of sensibility), is called notio. A concept made up of notions, which goes beyond the possibility of experience, is an idea or a concept of reason. (A320/B377)
3 Physical-hypothesis reading
We aim here precisely to derive actual empirical states of affairs from such hypothesized causes. These hypothesized ideas do impinge on the empirical, then, either (if unsuccessful) as disproven hypotheses or (if successful) as new empirical explanations or conceptualizations.(2017, 102-103)
4 Difficulties with the physical-hypothesis reading
[Ideas of reason] are merely thought problematically, in order to ground regulative principles of the systematic use of the understanding in the field of experience in relation to them (as heuristic fictions). If one departs from this, they are mere thought-entities, the possibility of which is not demonstrable, and which thus cannot be used to ground the explanation of actual appearances through an hypothesis. (A771/B799)
One must admit that one will hardly find pure earth, pure water, pure air, etc. Nevertheless, one requires concepts of them (concepts which, regarding their complete purity, have their origin solely in reason). (A646/B674)
5 The hypothetical use of reason
Among the different kinds of unity according to concepts of the understanding belongs the causality of a substance, which is called “power.” At first glance the various appearances of one and the same substance show such diversity that one must assume almost as many powers as there are effects, as in the human mind there are sensation, consciousness, imagination, memory, wit, the power to distinguish, pleasure, desire, etc. Initially a logical maxim bids us to reduce this apparent variety as far as possible by discovering hidden identity through comparison, and seeing if imagination combined with consciousness may not be memory, wit, the power to distinguish, or perhaps even understanding and reason. The idea of a fundamental power-though logic does not at all ascertain whether there is such a thing-is at least the problem set by a systematic representation of the manifoldness of powers. The logical principle of reason demands this unity as far as it is possible to bring it about, and the more appearances of this power and that power are found to be identical, the more probable it becomes that they are nothing but various expressions of one and the same
power, which can be called (comparatively) their fundamental power. (A648/ B676-A649/B677)
6 Particular chemical ideas are pure
The categories combined either with the modis of sensibility or with each other yield a great multitude of derivative a priori concepts [i.e., predicables], to take note of which and, as far as possible, completely catalogue would be a useful and not unpleasant but here dispensable effort. (A82/B108)
Although the entire world speaks of pure fire, pure water, pure air, etc., one must still admit that nothing is pure. We see, therefore, that we merely have effects in us to which we refer the types of matter and in view of the former we call the latter pure. Our reason makes certain classifications, which are prior to experience and in accordance with which we then organize our experience. (AA XXIX 161)
7 Particular chemical ideas contain natural kinds that are beyond the bounds of possible experience
8 Conclusion
References
Baumgarten, A. (2013). Metaphysics. C. Fugate & J. Hymers (Trans.). Bloomsbury.
Bickmann, C. (2002). Zur systematischen Funktion der Kantischen Ideenlehre. In R. Hiltscher & A. Georgi (Eds.), Perpektiven der Transzendentalphilosophie im Anschluß an die Philosophie Kants (pp. 43-79). Freiburg: Alber.
Carrier, M. (1990). Kants Theorie der Materie und ihre Wirkung auf die zeitgenönissische Chemie. KantStudien, 81(2), 170-210.
Cooper, A. (2022). Hypotheses in Kant’s philosophy of science. Studies in history and philosophy of science (online) (pp. 1-9).
de Boer, K. (2020). Kant’s reform of metaphysics: The critique of pure reason reconsidered. Cambridge: Cambridge University Press.
Ellis, B., & Lierse, C. (1994). Dispositional essentialism. Australasian Journal of Philosophy, 72(1), 27-45.
Engelhard, K. (2018). The problem of grounding natural modality in Kant’s account of empirical laws of nature. Studies in History and Philosophy of Science, 71, 24-34.
Frketich, E. (2019). Wolff and Kant on the mathematical method. Kant-Studien, 110(3), 333-356.
Horstmann, R.-P. (1998). Der Anhang zur transzendentalen Dialektik. In G. Mohr & M. Willaschek (Eds.), Immanuel Kant: Kritik der reinen Vernunft (pp. 525-545). Berlin: De Gruyter.
Karasek, J. (2015). Idee. In M. Willaschek, J. Stolzenberg, G. Mohr & S. Bacin (Eds.), Kant-Lexikon (pp. 1114-1116). Berlin: De Gruyter.
Klimmek, N. (2005). Kants System der transzendentalen Ideen. Berlin: De Gruyter.
Krausser, P. (1988). On the Antinomies and the appendix to the dialectic in Kant’s critique and philosophy of science. Synthese, 77(3), 375-401.
Kreines, J. (2008). Kant on the Laws of Nature: Laws, necessitation, and the limitation of our knowledge. European Journal of Philosophy, 17(4), 527-558.
Massimi, M. (2017). Grounds, modality, and nomic necessity in the critical kant. In M. Massimi & A. Breitenbach (Eds.), Kant and the Laws of Nature (pp. 150-170). Cambridge: Cambridge University Press.
Messina, J. (2017). Kant’s necessitation account of laws and the nature of natures. In M. Massimi & A. Breitenbach (Eds.), Kant and the Laws of Nature (pp. 131-149). Cambridge: Cambridge University Press.
McNulty, M. B. (2014). Kant’s philosophy of chemistry. UC Irvine Electronic Theses and Dissertations.
McNulty, M. B. (2015). Rehabilitating the regulative use of reason: Kant on empirical and chemical laws. Studies in History and Philosophy of Science, 54, 1-10.
Meer, R. (2019). Der transzendentale Grundsatz der Vernunft. Berlin: De Gruyter.
Okruhlik, K. (1986). Kant on realism and methodology: Progress beyond Newton? In R. E. Butts (Ed.), Kant’s Philosophy of physical science (pp. 305-329). Dordrecht: Reidel Publishing Co.
Rauscher, F. (2010). The appendix to the dialectic and the Canon of pure reason: The positive role of reason. In P. Guyer (Ed.), The Cambridge companion to Kant’s critique of pure reason (pp. 290-309). Cambridge: Cambridge University Press.
Spagnesi, L. (2022). The idea of god and the empirical investigation of nature in Kant’s critique of pure reason. Kantian Review, 27, 279-297.
Spagnesi, L. (2023). Regulative idealization: A Kantian approach to idealized models. Studies in History and Philosophy of Science, 99, 1-9.
Spagnesi, L. (2024). Natures, ideas, and essentialism in Kant. Synthese, 204, 1-26.
Stang, N. (2016). Kant’s modal metaphysics. Oxford: Oxford University Press.
Stratmann, J. (2022). The end of explanation: Kant on the unconditioned. Philosophy and Phenomenological Research, 105, 507-532.
von Varnbüler, T. (1890). Widerlegung der Kritik der reinen Vernunft. Prague: Hofbuchdruckerei A. Haase.
Watkins, E. (2019). Kant on infima species. In E. Watkins (Ed.), Kant on laws (pp. 212-224). Cambridge: Cambridge University Press.
Willaschek, M. (2018). Kant on the sources of metaphysics: The dialectic of pure reason. Cambridge: Cambridge University Press.
Zuckert, R. (2017). Empirical scientific investigation and the ideas of reason. In M. Massimi & A. Breitenbach (Eds.), Kant and the Laws of Nature (pp. 89-107). Cambridge: Cambridge University Press.
- Elise Frketich
efrketic@purdue.edu
Cornerstone Integrated Liberal Arts, Purdue University, West Lafayette, IN, USA I have modified the translation of this passage, and I explain why in sect. 4. References to Kant’s texts, with the exception of the Critique of Pure Reason, indicate the volume and page number of the Akademie Ausgabe of his Gesammelte Schriften, edited by the Preussische Akademie der Wissenschaften and published by De Gruyter. References to the first Critique cite the standard A (1781) and B (1787) editions, and I use the Guyer and Wood translation. Translations of untranslated texts are mine.
I follow Spagnesi in calling these ideas “particular ideas” (2022, 296). This name is fitting because Kant calls the specific metaphysical sciences, which feature such ideas, the “particular metaphysical sciences” (AA IV 470).
There is extensive research on Kant’s general transcendental ideas of reason. See, e.g., Bickmann (2002), Grier (2004), Klimmek (2005), and Willaschek (2018).
Kant discusses what he calls “physical hypotheses” in the section of the Doctrine of Method in the first Critique called “The discipline of pure reason in hypotheses” (A772/B800-A773/B801). I explain them in sect. 3.
E.g., Carrier (1990), McNulty (2014), and Meer (2019, 234-235). I thank an anonymous reviewer for encouraging me to expand on this point and to characterize it as a strength.
E.g., Kant explains that ideas contain the “unconditioned” (A311/B367), and he describes them as “imaginary focal points” (foci imaginarii) around which cognition is organized (A644/B672).
Scholars who list ‘pure’ and ‘has an extension that is beyond the bounds of possible experience’ as the defining features of ideas in general are Karasek (2015, 1114ff) and Horstmann (1998, 535).
Kant indicates that ideas are pure and have an extension that is beyond the bound of possible experience in the Stufenleiter (A320/B377). However, some Kant scholars question whether these features apply to all species of ideas, especially in the cases of, e.g., practical and aesthetic ideas. Okruhlik likewise states that particular ideas are idealizations of things found in nature . See also: “The ideas of the pure elements are also, like the ideas proper, posited object-representationsrepresentations of purported objects that are to be governed by the laws we hope to find. Importantly, unlike the ideas of reason, however, the objects of these ideas are not necessarily or irrevocably beyond experience” (Zuckert, 2017, 102). For the view that the particular ideas of reason can become empirical concepts if instances of them are discovered in nature, see further Rauscher (2010, 296-297n5). Okruhlik outright denies that particular ideas have an extension that is beyond the bounds of possible experience . See, e.g., Cooper (2022, 7). Cooper uses as an example McNulty’s description of a chemist, who “reduces all the metals to earth, and measures their weight, all the salts to combustibles, and measures their force, and examines water and air as vehicles, measuring their mechanical properties” (2022, 7). However, it is unclear whether McNulty subscribes to the same theory of hypotheses as does Cooper.
Cooper likewise makes this point (2022, 6). Spagnesi likewise emphasizes that, for Kant, ideas cannot be used in physical hypotheses (2023, 5).
See further, e.g., McNulty (2015, 2).
Kant puts this point as follows: “If the imagination is not simply to enthuse but is, under the strict oversight of reason, to invent, something must always first be fully certain and not invented, and that is the possibility of the object itself” (A770/B798). The original German rules out the latter option because the pronoun “die” in the parentheses must refer to the closest noun with the matching gender according to German grammar, and that is “die Begriffe”. It cannot refer to the group of contents listed in the prior sentence, e.g., pure earth and pure water, because there is a suitable noun that is closer to it than this group. Furthermore, it cannot refer to this group via the “davon” in the same sentence because the latter is, in this context, grammatically inseparable from “die Begriffe”, which brings us back to the same result.
See, e.g., Digitales Wörterbuch der deutschen Sprache and Duden. See further (AA IX 92).
See: “When we call something an idea, we are saying a great deal about its object (as of an object of pure understanding), but just for this reason very little about the subject (i.e., in respect of its actuality under empirical conditions), since, as the concept of a maximum, nothing congruent to it can ever be given in concreto.” (A327/B384, translation slightly modified). Note that this is a universal statement about all ideas, not a statement that can be read as applicable only to the general transcendental ideas.
E.g., McNulty provides a convincing argument for the claim that the particular chemical ideas are a priori, i.e., the object of a particular idea must be a priori to explain the possibility of the necessity of empirical laws (2015, 3-7). However, he does not provide one for the claim that they are pure, and ‘a priori’ does not have the same meaning as ‘pure’ for Kant, even if what is a priori is often also pure (e.g., A20/B34). Furthermore, he does not solve the puzzle of how something that must in some sense originate in experience could be pure.
E.g., McNulty provides two arguments for the claim that the objects of particular chemical ideas are beyond the bounds of possible experience. The first builds on the one that I discuss in the previous footnote: the object of a particular idea must be a priori and unconditioned to explain the necessity of empirical laws, and if such an object is a priori and unconditioned, then it must also be beyond the bounds of possible - experience (McNulty, 2015, 3-5). The second is an argument from definition: all ideas are unconditioned (and therefore beyond the bounds of possible experience), particular chemical ideas are ideas, therefore, particular chemical ideas are unconditioned (McNulty, 2015, 5n25). While I find these arguments convincing, Zuckert, e.g., must not have been convinced by the first because her paper that claims the opposite was published after McNulty’s, and she would deny the minor premise of the second because she holds that particular chemical ideas are not ideas properly speaking (2017, 99; 102-103).
To best understand the hypothetical use of reason, it is helpful to consider the contrast that Kant draws between it and what he calls “the apodictic use of reason” (A646/B674). Both are inferential activities, according to him, but they differ with respect to the epistemic status of their premises. In the apodictic use of reason, the major premise is known to be true, and this necessarily and universally so (A646/B674). E.g., we know that the proposition “three non-linear points always lie on a plane” is necessary and universal because, for Kant, we have evidence of its truth in a priori intuition (A732/B761). We can then use this proposition as a major premise in an apodictically certain syllogism. The principle of parsimony is also frequently referred to as Ockham’s Razor. Kant calls the principle of the systematic unity of reason “the parsimony of principles” (A650/B768), and he cites its Latin expression, “entia praeter necessitatem non esse multiplicanda” (“one should not multiply beginnings (principles) without necessity”) (A652/B680). On my interpretation, reason, in its hypothetical use, not only acts in accordance with the principle of parsimony when generating particular ideas, but it also follows what Kant calls the “logical maxim” and “supreme principle” of pure reason, which he introduces at the beginning of the Transcendental Dialectic. The logical maxim states that reason is “to find the unconditioned for conditioned cognitions of the understanding, with which its unity will be completed” (A307/B376). In short, we seek the condition, i.e., cause, for any conditioned thing until we arrive at something that is unconditioned, i.e., uncaused. For a recent discussion of this maxim in the Kant scholarship, one that gives examples of different kinds of conditioning relations, see Spagnesi (2022, 2). The supreme principle states that “we assume that when the conditioned is given, then so is the whole series of conditions subordinated one to the other, which is itself unconditioned, also given (i.e., contained in the object and its connection)” (A307-308/B364). In short, we assume that if the conditioned exists, then so too exists the entire series of conditions. On my interpretation, the two steps in the example in the main text, including when we reduce the relatively fundamental power to a fundamental one, model the logical maxim. When we then posit the existence of this fundamental power, on my interpretation, this example models Kant’s supreme principle. This interpretation is controversial. Many Kant scholars hold that only the three highest ideas are unconditioned. While I think that particular chemical ideas are likewise unconditioned, I cannot argue for this claim here. I thank an anonymous reviewer of Synthese for urging me to include this point.
I thank an anonymous reviewer of Synthese for this pithy description of the hypothetical use of reason. Note that all assertoric (real) and apodictic (necessary) judgements are also possible (problematic), but not all possible judgements are real or necessary. An assertoric judgement must also be evidenced in intuition and an apodictic judgement is determined through the “laws of the understanding” (A75/B101-A76/ B101).
This description allows for another important contrast between apodictic and hypothetical premises, this time regarding the way that they relate to their respective conclusions. An apodictic premise imparts its truth to the conclusions that follow from it. E.g., under the already-seen apodictic premise that “three nonlinear points always lie on a plane”, we can subsume the following minor premise, which we gain from experience: ‘A, B, and C are three non-linear points’. From these two premises we deduce that ‘A, B, and C lie on a plane’, proving the truth of this conclusion with certainty. By contrast, a hypothetical premise does not have any verifiable truth to impart to the conclusions that follow from it. Instead, we can only verify the truth of these conclusions and attempt to impart it to the hypothetical premise. We can see this in the above-cited passage regarding the fundamental power of the human mind when Kant states that “the more appearances of this power and that power are found to be identical, the more probable it becomes that they are nothing but various expressions of one and the same power”. We know that propositions about appearances of various powers of the mind are true thanks to our observations of them. Yet, we do not know the truth of our hypothetical premise, namely, that these appearances are caused by a fundamental power of the mind. However, if more and more true propositions about these appearances can be derived from our hypothesis, then it becomes more probable.
The only kind of real possibility that has been attributed to particular chemical ideas in the Kant scholarship, as far as I am aware, is the kind that I treat in the main text, and I take myself to show that this kind does not hold of particular chemical ideas. However, Nick Stang forcefully argues that Kant employs additional kinds of real possibility in the first Critique, ones that Kant does not explicitly explain. While it is beyond the scope of this paper to investigate whether an additional kind of real possibility could be attributed to particular chemical ideas, this would be an interesting avenue for future research. A promising avenue for proving a higher-order or pure hypothesis is one that draws on what Kant says about the sufficient grounds for a claim in the section of the first Critique called “On having opinions, knowing, and believing”. See further, e.g., Cooper (2022, 8). Some Kant scholars may hold that a predicable cannot be a feature of an idea of reason because there seems to be a contradiction between predicables and ideas, i.e., predicables are derived, and ideas are unconditioned and therefore not derived. However, I hold that there is no contradiction because, first, predicables and ideas are “derived” and “not derived” in two different senses. The derivation of predicables remains on the level of transcendental logic. The derivation itself does not have ontological import, but rather it only serves to complete the non-fundamental aspects of our table of categories. By contrast, the derivations of which ideas of reason stand at the head have ontological import. They aim at tracking real causal relations (see, e.g., Spagnesi, 2024, 5-6). Furthermore, even if both derivations had ontological import, it would still not be contradictory to include predicables in concepts of reason because something can be unconditioned with respect to one conditioning relation and conditioned with respect to another for Kant (see Willaschek, 2018, 87-98; Stratmann, 2022, 512). Finally, my claim that it is non-contradictory to include predicables as features in ideas of reason is verified by Kant himself as he uses a predicable, namely, ‘incorruptible’, as a feature of an idea of reason, namely, the idea of the soul, as I discuss in the main text.
Since Kant lists corruption as a predicable, its negation must also be a predicable (A82/B108).
Kant calls the idea of pure water a “vehicle” at A646/B674. In the Danziger Physik, he equates a vehicle with a “commercium”, which he describes as the interaction between an active and a passive power (AA XXIX 161). Since the context here is a discussion of mechanics, we can best understand this general description of interaction as one of a material instead of an immaterial interaction. Furthermore, Kant usually uses ‘commercium’ to refer to the interaction of substances in space and time (e.g., A214/B261-A215/ B262, AA XXVIII 215, AA XXIX 854, AA XXIX 853, and AA XXIX 868). I thank an anonymous reviewer for pushing me on this point.
Kant lists the powers whose actualizations that pure water enables in the following: “Earths are the onus, the negative matter that do not have a power to dissolve but rather are to be dissolved. In nature, salt and combustible things are the two potentiae that dissolve everything. […] Salts require water as a vehicle in order to act as powers to dissolve” (AA XXIX 161). Kant reiterates these two steps in the Prolegomena: “As was proper, I called them categories, after their ancient name, whereby I reserved for myself to append in full, under the name of predicables, all the concepts derivable from them – whether by connecting them with one another, or with the pure form of appearance (space and time) or its matter, provided the latter is not yet determined empirically (the object of sensation in general) – just as soon as a system of transcendental philosophy should be achieved, on behalf of which I had, at the time, been concerned only with the critique of reason itself” (AA IV 324).
Note that Baumgarten defines ‘ontology’ as “the science of the more general predicates of a being” (2013, §4). This definition excludes his rational cosmology, psychology, and theology. However, Kant must have had Baumgarten’s entire Metaphysics in mind, including these three branches of philosophy, because Baumgarten only introduces pure concepts like ‘immortal’ in his rational psychology (2013, §781), a concept that Kant attributes to ‘soul’ (A345/B403). As we have seen, for Kant, ‘vehicle’ refers to a material substance that enables the interaction between an active and a passive power, one that is subject to the laws of motion. Furthermore, Kant equates a vehicle with what is called a “machine” (e.g., A646/B674 and AA 29:161). Baumgarten includes ‘machine’ in his metaphysics, which he describes as “a composite being in the strict sense that is moveable according to the laws of motion” .
Some Kant scholars might view this conclusion as too hasty. They might think that Kant’s Metaphysical Foundations of Natural Science (henceforth: MFNS) could likewise be a source of predicables because, in it, Kant undertakes an a priori determination of the concept of matter according to the four types of categories (4:476). While we can indeed locate the ‘power to dissolve’ in the section of MFNS that treats Kant’s theory of dynamics, a problem here arises. We are unable to locate the powers proper to the other particular chemical ideas in it. Thus, appeal to MFNS cannot explain the purity of Kant’s particular chemical ideas either. As Kant puts this point, “only an apodictic proof, insofar as it is intuitive, can be called a demonstration. […] Thus only mathematics contains demonstrations” (A734/B762). Only mathematics is capable of apodictically certain demonstrations, for Kant, because we can only know a premise to be necessarily true-which is a condition of the apodictic use of reason (see note 23)-when we exhibit it in a priori intuition as Kant thinks we do with, e.g., such pure mathematical concepts as that of the triangle. By contrast, according to Kant, philosophy is incapable of necessary premises because it is incapable of strict definitions and axioms (A727/B755-A733/B761). For more on the mathematical method, see Frketich (2019).
See, e.g., AA IV 468; 471. For a detailed discussion of the empirical nature of chemistry due to experimentation as well as the scientific context that Kant alters by positing a pure, albeit problematic ground for this empirical science, see Meer (2019, 224-233). For a detailed discussion of particular chemical ideas as the pure ground of empirical chemistry, see McNulty (2015).
The claim that the object of a particular chemical idea is a natural kind is already maintained by several Kant scholars, e.g., Kreines (2008, 540), McNulty (2015, 6n36), and Spagnesi (2024, 8), which provides further support for my view that this object is a universal-not a hypothetical spatiotemporal object that figures in a physical hypothesis-that is beyond the bounds of possible experience.
I follow de Boer in calling these concepts the “concepts of reflection”, and my description of them is indebted to hers (de Boer, 2020, 191-211). - 43 “It is thereby said that the nature of things themselves offers material for the unity of reason” (A652/ B680).
In addition to the principles discussed in note 24, the “principles of reason” refer to the principles of homogeneity, specification, and continuity (A657/B685-A658/B686). The principle of homogeneity guides the production of genera in our system of concepts. The principle of specification ensures that species are generated to be subsumed under each genus. Finally, the principle of continuity of forms requires that there be no gaps between any genus and species. For a detailed account of these principles, as well as how they contribute to systematizing cognitions, see Watkins (2019). See note 41 for further Kant scholars who hold this view.
Kant knew that chemistry was revising its understanding of the nature of chemical elements in the 18th century, even after the publication of . Since the particular ideas of chemical elements are generated to explain certain empirical cognitions, cognitions whose explanatory needs can change with new empirical information, I hold that lower ideas can change or be replaced. E.g., Kant replaces the particular idea of pure air with that of phlogiston in the Danziger Physik (AA XXIX 161; see McNulty, 2014, 92n138). See further Krausser, who describes this process as a feedback cycle between sense data and Kant’s system of reason (1988, 397-389). The changeable nature of particular ideas is compatible with my view that their objects are universals because these universals are mind-dependent schemata that serve to organize cognitions on my interpretation. When one particular idea no longer fits the empirical data, the mind will replace it with one that does, resulting in a new particular idea of a chemical element with a new schema or universal. I thank an anonymous reviewer of Synthese for pushing me to clarify this point.
For more detailed accounts of this claim, see, e.g., Massimi (2017), Messina (2017), and Engelhard (2018).
I agree with Carrier (1990) and McNulty (2015), who also claim that elements bear powers for Kant. While the individual members of the group embody the features of a material substance because they are physical individuals in space and time, the schema-the object of the idea of a pure chemical elementmerely designates these features, just as the features of a concept do. Although Rauscher is a proponent of the received view, we agree that there are many different types of particular ideas, including biological species (2010, 295-296).
I thank an anonymous reviewer of Synthese for encouraging me to characterize this as a strength of my reading and for guiding my discussion of the third Critique. I began this paper during a research stay at the University of California, San Diego, where I had the pleasure of discussing it with Eric Watkins, Clinton Tolley, and their research group. Since then, I have received further invaluable comments from several scholars on multiple drafts, including Dina Emundts, Pat Kain, Karen Koch, Jacqueline Mariña, JP Messina, Chen Yang, Chris Yeomans, and Pavel Reichl. The research for this paper was funded by a short stay abroad grant, awarded by the Flemish Research Council, and a research fellowship at the “Human Abilities” Centre for Advanced Studies in the Humanities in Berlin.
