Kant’s Philosophy: Metaphysics, Ethics, and Political Ideals
Kant’s Examination of Metaphysics and the Sciences
Kant examines the conditions that enabled the physical and mathematical sciences to develop and attempts to apply these conditions to metaphysics.
Classification of Judgments
The study of the qualifications of physics and mathematics requires an examination of judgments within these disciplines. This leads Kant to a classification of judgments according to two criteria:
According to the relationship between subject and predicate, there are two types of judgments:
- Analytic judgments: The information in the predicate is already contained within the subject. These judgments are strictly universal and necessary but do not expand our knowledge.
- Synthetic judgments: The predicate provides new information about the subject, but it is not necessarily true.
According to the relationship of judgment to experience, there are two types of judgments:
- A priori judgments: Their truth is independent of any experimental verification. They are universal and necessary judgments.
- A posteriori judgments: Their truth can be established only after experimental verification. These judgments can be neither universal nor strictly necessary.
Sensibility
Capturing a sense from a subject is an immediate form of knowledge that Kant calls sensible intuition, and the object is a phenomenon. A phenomenon is composed of matter, which is the content of sensation, and form, which is the way the sensation is captured by the subject. Space and time are the two elements of our sensitivity with which we shape sensible intuitions. They are a priori forms of sensation or pure intuitions (without matter).
The Basis of Mathematical Judgments
- The synthetic a priori judgments of mathematics (arithmetic and geometry) are based on a priori forms of sensibility (space and time).
- Geometry studies the properties of space, and arithmetic studies the properties of time. Any valid judgment made in relation to one or another discipline will be a priori and, therefore, strictly universal and necessary.
Reasoning
In our pursuit of knowledge, we do not just build judgments; we chain them together reasonably. Syllogisms are the kind of reasoning in which the truth of the conclusion is true, provided that the assumptions are valid. Human beings tend to exceed the limits of their ability to understand and apply categories to that of which there is no sensible intuition. According to Kant, there are three kinds of syllogisms, each of which yields an idea of pure reason:
- Categorical syllogisms lead us to the idea of the soul.
- Hypothetical syllogisms lead us to the idea of the world as a whole.
- Disjunctive syllogisms lead us to the idea of God.
Since we have no sense impression of any of these three ideas, an error is made. The function of categories is to order what is intuited in space and time. Therefore, when applied to noumena, it is an illegitimate use of them, and the results are illusions, that is, false knowledge.
Practical Reason and Morality
The critique of reason is not limited to the realm of theoretical knowledge of reality but also covers the practical field of morality. Universality is, for Kant, a prerequisite of morality (moral law, to be acceptable, must be true for every human being).
Material Ethics
Material ethics are those that have content, proposing an end to be achieved and standards to achieve it. Kant believes that this type of ethics has three fundamental flaws:
- They are empirical, meaning we can only propose an end as good and standards to achieve it after having experienced it.
- They present hypothetical imperatives: the proposed regulations are valid only if one accepts the proposed order.
- They are heteronomous because reason is not given the rules itself; they are mandated by feeling or inclinations.
Formal Ethics
Formal ethics are void of content. They do not tell us what to do but how to act. Formal ethics have none of the three defects of material ethics:
- They are a priori rather than empirical.
- Their imperatives are categorical rather than hypothetical.
- They are autonomous since reason gives the law to itself.
Duty
What determines the moral worth of an action is its relationship to duty:
- Actions contrary to duty are immoral actions.
- Actions in accordance with duty are legal actions but are not moral because they are performed for a reason unrelated to duty (e.g., to avoid punishment, gain recognition).
- Actions performed out of duty are truly moral actions.
Duty is respect for the practical law that is expressed in the categorical imperative: “Act always on a maxim that you want to become a universal law.” This imperative is universal and formal, as it does not say what to do but how to act. According to the categorical imperative, what is decisive for an action to be moral is not what you actually do but the intention with which you do it.
Politics Within Reason
Human hope transcends the goals of immanent religion and encompasses objectives that are the proper task of politics. That rational hope placed in politics is summarized in the following ideas:
- Achieve an enlightened age in which all adult humans are capable of using reason without the guidance of others.
- Build a state of free citizens who use their reason and respect the laws.
- Create a federation of free states to avert the danger of war.