Kant’s Metaphysics: A Priori Knowledge, Synthetic Judgments, and Ethics
1. – The General Problem of Metaphysics
Metaphysics has failed to enter the secure path of science. Unlike other sciences, metaphysics has sought to transcend experience and offer knowledge of entities such as God, the soul, and the world as a whole, from a priori concepts independent of experience.
2. – The Problem of A Priori Knowledge
Since metaphysics seeks to obtain a priori knowledge independent of experience, the answer to the question about its ability to provide answers precedes the question of whether a priori knowledge is possible. But how many ways are there to knowledge? Is a priori knowledge genuine, or just an illusion? Unlike rationalists and empiricists, who believed in a single source of knowledge (reason or experience, respectively), Kant proposed two sources: sensitivity, providing the matter of knowledge from experience, and understanding, supplying the form of knowledge, independent of experience. We distinguish between a priori knowledge (absolutely independent of all experience) and a posteriori knowledge (empirical knowledge, possible only after experience). Empirical knowledge is neither universal nor necessary. However, certain knowledge (e.g., mathematics) involves necessity and universality. If these cannot come from experience, they must be a priori. Kant appeals to science in general, mathematics, and physics as examples. Unlike Hume, who considered the principle of causality dependent on experience, Kant stated it as a universal and necessary principle, thus a priori. Recognizing the existence of a priori knowledge, Kant questioned its foundation and legitimacy. Since all knowledge is expressed in judgments relating a subject and a predicate, he explored the different types of possible judgments.
3. – Analysis of Judgments: Synthetic A Priori Judgments
Following Leibniz’s distinction between truths of reason and truths of fact, and Hume’s distinction between relations of ideas and matters of fact, Kant distinguished two types of judgments: analytic and synthetic. In analytic judgments, the predicate is included in the subject and thus provides no new information (e.g., “A triangle has three angles”). Analytic judgments are always true and a priori. Synthetic judgments are those in which the predicate is not included in the subject and provide new information (e.g., “Bodies are heavy”). Both Leibniz and Hume would agree that such judgments are all a posteriori, dependent on experience. However, Kant distinguished between synthetic a priori and synthetic a posteriori judgments. While the latter are contingent and dependent on experience, the former, being a priori, contain universal and necessary knowledge, yet, being synthetic, increase our knowledge.
Example of Synthetic A Priori Judgments
As an example of synthetic a priori judgments, Kant suggests: “Everything that happens has a cause.” He also refers to other synthetic a priori judgments in various sciences, such as the proposition “7 + 5 = 12” in mathematics (12 is not contained in the idea of adding 7 and 5, making the judgment synthetic and increasing our knowledge, yet it is universal, necessary, and a priori). Kant devoted the fifth chapter of the introduction to showing that “all theoretical sciences of reason contain synthetic a priori judgments as principles.” This means that such judgments are not only present in science but also form its foundation. Until then, it was accepted that analytic a priori judgments were the foundation of mathematics and synthetic a posteriori judgments the foundation of natural science. Kant’s assertion of a third type, synthetic a priori judgments, as the foundation of science, was surprising and controversial.
Correspondence between the functions of unity, the kinds of judgments, and categories
- Quantity: Universal, Particular, Singular
- Quality: Affirmative, Negative, Infinite
- Relation: Categorical, Hypothetical, Disjunctive
- Modality: Problematic, Assertoric, Apodictic
Table of Categories
- Quantity: Unity, Plurality, Totality
- Quality: Reality, Negation, Limitation
- Relation: Inherence and Subsistence (Substance and Accident), Causality and Dependence (Cause and Effect), Community (Interaction)
- Modality: Possibility-Impossibility, Existence-Non-Existence, Necessity-Contingency
Kant’s claim that synthetic a priori judgments are a novelty raises three questions:
- How is pure mathematics possible? (Answered in Kant’s Transcendental Aesthetic)
- How is pure natural science possible? (Answered in Kant’s Transcendental Analytic)
- Can metaphysics be a science? (Answered in Kant’s Transcendental Dialectic)
Kant’s Copernican Revolution
Hitherto, philosophers assumed that the subject was to be subjected to things, but as of now, things are supposed to be subjected to the subject, understanding this as synthetic a priori knowledge. This inversion of the role of subject and object in knowledge is Kant’s “Copernican revolution.”
Sensitivity and Understanding
Unlike rationalists and empiricists, who conceived of a single source of knowledge (reason or experience, respectively), Kant proposed that knowledge results from the collaboration of both: sensitivity receives objects, and understanding thinks them. Kant claims that both sensitivity and understanding have transcendental forms, which are a priori and independent of experience, and without which no knowledge is possible.
Sensitivity (Transcendental Aesthetic)
Sensitivity is the ability to perceive objects and the means by which we perceive them. Knowledge referring to an object is called intuition by Kant, and the effect of an object on our ability to sense representation (sensation) is called affection. In sensitivity, reference to an object is called sensible or empirical intuition. The object of an undetermined empirical intuition (its cause) is called a phenomenon. In a phenomenon, we can distinguish matter and form. The matter corresponds to sensation. The form is “what makes it different from the same” and allows it to be ordered in certain relations. We cannot perceive objects without space and time. Space and time are pure a priori forms of sensibility. To explain how synthetic a priori judgments are possible in mathematics, Kant speaks of the determinations of space (geometry) and time (arithmetic). Geometry analyzes the properties of space, and arithmetic analyzes the properties of time. Since space and time are the conditions under which every phenomenon is given, the properties of space and time are necessarily transmitted to any phenomenon occurring in them. Thus, all mathematical knowledge must be universal and necessary, as all phenomena must exist in space and time. This makes synthetic a priori judgments possible in mathematics, i.e., judgments that increase knowledge and yet are independent of experience, and therefore universal and necessary.
Understanding (Transcendental Analytic)
Understanding is the power of thinking about objects given in intuition. It works with concepts. Thinking is the same as making a judgment (linking two concepts). Sensible intuitions, if not thought through a concept, would offer no knowledge. Concepts, if not referred to a sensible intuition, offer empty knowledge. “Intuitions without concepts are blind, concepts without intuitions are empty.” If we separate the matter and form of understanding, as we did with sensitivity, we can distinguish two types of concepts: empirical concepts and pure concepts or categories. Empirical concepts result from generalizations from experience. Pure concepts are a priori and are the structures from which empirical concepts are generated, enabling judgments. Kant classifies these judgments into categories, and according to their form, into four types, each with three possibilities:
- Quantity: Universal, Particular, Singular
- Quality: Affirmative, Negative, Infinite
- Relation: Categorical, Hypothetical, Disjunctive
- Modality: Problematic, Assertoric, Apodictic
11.
We are now ready, then, to understand how synthetic judgments are possible a priori in the natural sciences. Recall the example we put Kant: “any changes must have a cause.” It is a synthetic view, since the notion of change does not include the cause, and a trial is a priori, independent of experience, and therefore universal and necessary, it is based on the category of causality and dependence (cause and effect). The possibility of metaphysics. (The transcendental dialectic.) Mathematics and physics can make synthetic judgments a priori and, therefore, of achieving universal and necessary knowledge, scientific knowledge. But can do metaphysics? Understanding is the ability to judge, ie to attribute a predicate to a subject by formulating a juicio.El reasoning consists in linking trial by formulating syllogisms. Analyzing the forms of syllogisms, concludes that three transcendental ideas: soul, world and God. By the idea of soul, Kant says, we unify all the phenomena of the psyche. World through the idea of unifying all the phenomena of experience. By the idea of God unify the totality of psychic phenomena and experience in a single source on which they depend and which are explained.But though the transcendental ideas help us to unify the thinking of all the phenomena, whether mental or outer experience, intuition is not and has none of the realities to which refers the unity of phenomena (God, soul, world ) these transcendental ideas conocimiento.La not offer us any metaphysics, then, is impossible as science: that knowledge has an empirical content has to be subsumed under one category, but the objects of metaphysics (God, world and soul) We have no empirical content. They are pure concepts of reason, form ideas trascendentales.Principio
Final Form
Formal Ethics. The moral knowledge is not knowledge of being but an understanding of what it should be. Kant distinguishes use theoretical and practical use of reason. In its theoretical use, it is thought a priori knowledge by understanding, is real and exists in experience. In practical use, is ideal, and has no validity with respect to knowledge. I think there will and ethical system in experiential, is a conception of the good as the object of morality. Man receives from outside the moral law of reason, so it really is not acting freely, losing the ability to self-determination of their conduct, the autonomy of the will. Morality can not be based on anything empirical. A moral norm must be universal, it must hold for all men in all circumstances, and must be necessary, is enforceable by itself. The moral law is based on the notion of duty. But as the moral law is universal and necessary order or command containing it must be categorical, ie can not be subject to any condition (can not be hypothetical). The formula which expresses that mandate or order of the moral law will call Kant’s categorical imperative, which is a judgment-practical synthetic a priori. However, as the moral law can not contain anything empirical, the categorical imperative which expresses neither shall have any empirical content, but only the pure form of morality. Kant gives three different definitions of the categorical imperative: 1.-Act so that the maxim of your will is worth, always at the same time, as a principle of law universal.2.-Work as if the will. For its maximum, can be regarded itself as a universal law. 3 .- Act in such a way that you use humanity, whether in your person and in the person of any other, always as an end and never as a means. “Postulates práctica.El man of reason must be free to implement morality and should not be predetermined. There must be an immortal soul because, if man can not achieve its purpose in this life, it have a future life as a guarantee for the attainment of moral perfection and a God must exist to ensure this, as it is in God where morality and happiness coincide.