Immanuel Kant: Philosophy of Transcendental Idealism
Immanuel Kant
Critique of Pure Reason
One of Kant’s major works, the Critique of Pure Reason, addresses the limits and scope of human knowledge, exploring the possibility of empirical science and metaphysics. Kant’s work was influenced by several key movements and thinkers:
Influences
- Rationalism: “Nothing is in the intellect that has not been received by the senses, except the understanding itself.”
- Empiricism: Scientific knowledge is grounded in experience, suggesting the possibility of metaphysics as a science.
- Newtonian Physics: The physical world operates under strict necessities discoverable by reason.
- The Enlightenment: Humans are both social and individual, striving for autonomy and self-governance. “History is in steady progress towards the best.”
- Pietism: This variant of Lutheran Protestantism emphasizes a direct, personal, and subjective relationship between God and humanity. Morality is based on good works rather than external piety.
Limits of Metaphysics
Kant argued that human theoretical reason cannot know metaphysical realities like the self, the world, and God. However, this ignorance doesn’t imply denial. We should obey our conscience and pursue moral good, regardless of God’s existence.
A Priori and A Posteriori Knowledge
Kant distinguishes between a posteriori knowledge (known after experience) and a priori knowledge (independent of experience). Human knowledge begins with sensory impressions received by our sensibilities. These impressions are organized in time and space, resulting in phenomena. Understanding then conceptualizes this empirical information, producing knowledge.
Space and Time
- Space and time are not objective, absolute realities, but a priori forms of our sensibility.
- They are pure intuitions, empty of content.
Concepts of Understanding
- Empirical Concepts: Applied to concrete phenomena based on experience.
- Pure Concepts (Categories): A priori forms of understanding, independent of experience. These categories are empty of content but organize and structure phenomena.
Knowledge requires conceptualization. We only truly know something when a concept is applied to empirical data (phenomena). Human knowledge relies on both experience and understanding. The object influences the subject, and the subject influences the object. We can only know phenomenal reality, not noumenal realities (God, the world, the self).
Judgments
Kant categorizes judgments based on form and subject:
Form
- Analytic Judgments: The predicate is contained within the subject (e.g., “The whole is greater than its parts.”).
- Synthetic Judgments: The predicate is not contained within the subject (e.g., “The average height is 1.70m.”).
Subject
- A Priori Judgments: Content is independent of experience.
- A Posteriori Judgments: Content depends on experience.
Types of Judgments
- Analytic A Priori: (e.g., “The whole is greater than its parts.”)
- Synthetic A Posteriori: (e.g., “The average height is 1.75m.”)
- Synthetic A Priori: (e.g., “The line is the shortest distance between two points.”)
Mathematics and physics provide universal and necessary scientific knowledge. Every effect has a cause. Metaphysics cannot be a science because it cannot produce synthetic a priori judgments.
Philosophical Consequences
- Subjectivism: We know objects as we understand them, not necessarily as they are.
- Phenomenalism: We can only know phenomena, not the noumenal realm behind them.
- Transcendental Idealism: We only know the transcendental, the sense impressions and the understanding that receives them.
- Criticism: We must define what can and cannot be known.
Kantian Ethics
- Ethics must be a priori, derived from reason, not experience.
- Moral action is disinterested, not performed for a particular purpose.
- Categorical Imperative: Unconditional moral mandates that apply to everyone. Act out of duty and only duty.
- Autonomy: Individuals must use reason to discover duty for themselves.
We must act from duty, not merely according to duty, and never for personal gain. The categorical imperative commands unconditionally. “Act only according to that maxim whereby you can at the same time will that it should become a universal law.”
Freedom
- Positive Freedom: Doing something even if the body doesn’t need it.
- Negative Freedom: Doing what the body needs.
Postulates of Practical Reason
- Freedom: Duty requires freedom to act.
- Immortality of the Soul: Moral perfection is unattainable in this life, requiring another life for completion.
- Existence of God: While God’s existence cannot be rationally proven or denied, assuming it is not unreasonable.
Rational End of History
is the fulfillment of moral law that every rational being knows and has written on the inside.
This moral law is specified in the full development of human rationality, human freedom in society and perpetual peace between peoples.
These objectives have been achieved with the free participation of humans.
In Kant’s religion is somewhat reduced to morality.