Hume, Kant, Mill: Core Philosophical Concepts
David Hume’s Philosophy
Knowledge and Experience
According to Hume, we have nothing in our minds that we haven’t received through experience. Our perceptions consist of impressions (direct sensory input) and ideas (fainter copies of impressions). Imagination combines and rearranges ideas. The laws of association of ideas explain how ideas connect:
- Similarity
- Contiguity (in time or place)
- Causality (cause and effect)
These laws explain the formation of abstract ideas, which are not directly derived from experience.
Science, Induction, and Causality
The problem of induction arises because our expectation that the future will resemble the past is based on habit or custom, not logical certainty. We believe this conformity will continue, but it’s not guaranteed. The idea of causality, the supposed necessary connection between cause and effect, is not derived from experience because we never have a direct sensory impression of this connection. When we observe what we call a causal relationship, we only experience:
- Temporal priority (cause precedes effect)
- Spatio-temporal contiguity (cause and effect are close in space and time)
- Constant conjunction (the pairing has always occurred in our experience)
Therefore, empirical knowledge of a necessary causal link is impossible. Possible sciences include physics, chemistry, and natural sciences. Hume distinguishes two types of reasoning:
- Relations of Ideas: Knowledge derived from logic and definition (e.g., mathematics). It is certain but tells us nothing about the world.
- Matters of Fact: Knowledge derived from experience. It tells us about the world but is never absolutely certain.
Metaphysics and Skepticism
Hume argues that we cannot perceive a continuous, unchanging self; we only perceive a bundle of changing perceptions. We cannot be certain that our impressions correspond accurately to an external world, nor can we rationally prove or disprove the existence of God. These conclusions lead towards:
- Phenomenalism: We only know phenomena (appearances), not underlying reality.
- Idealism: Reality is fundamentally mental or based on ideas (though Hume is more skeptical).
- Skepticism: Doubting the possibility of certain knowledge, especially regarding metaphysics. Hume advocated for a moderate, theoretical skepticism.
Morality, Politics, and Religion
Hume proposed moral emotivism: moral judgments (‘good’ and ‘bad’) are based on feelings or sentiments of approval or disapproval, not reason. Reason is the ‘slave of the passions,’ helping us achieve what we desire. Freedom means the absence of external constraints preventing us from acting on our desires. Political structures are deemed necessary and useful for social order. Regarding religion, Hume maintained that we cannot rationally demonstrate the immortality of the soul or the existence of God.
Immanuel Kant’s Ethical Framework
Formal Ethics and Duty
Kant’s ethics are a priori (derived from reason, independent of experience), disinterested (not based on personal gain), autonomous (self-legislating), and universal. The core principle is the categorical imperative: act only according to that maxim whereby you can at the same time will that it should become a universal law. Morality is based on duty, acting out of respect for the moral law.
Postulates of Practical Reason
While they cannot be proven theoretically, Kant argues that practical reason requires us to postulate:
- Freedom: Morality requires that we are free to choose our actions (‘ought implies can’).
- Immortality of the Soul: Achieving moral perfection (holiness), the ultimate goal, requires an infinite progression, possible only if the soul is immortal.
- Existence of God: To guarantee that happiness is eventually proportioned to virtue, ensuring the moral endeavor is not ultimately futile.
Ethical Rationalism
Morality originates from a priori reason, independent of experience or consequences. Kantian ethics emphasizes formalism: the moral worth of an action lies in its form (the maxim or principle behind it) and its adherence to the categorical imperative, not its results. Morality is thus universal and necessary.
J. Stuart Mill’s Philosophy
Knowledge and Science
All knowledge comes from experience and sensible intuition, verified through observation and testing (empiricism). Universal ideas are merely names (nominalism) used to group objects with shared features. Metaphysics, seeking knowledge beyond experience, is impossible. Science relies on induction (observing particular instances) and subsequent generalization to formulate general laws. These laws are highly probable but not absolutely certain. Possible sciences include:
- Physical Sciences: Physics, chemistry, natural sciences, mathematics.
- Moral Sciences: Psychology, sociology, ethology (the science of character formation).
Human Nature and Freedom
Mill leaned towards determinism, suggesting humans lack metaphysical free will. However, practical freedom means acting without external coercion or constraint.
Utilitarian Morality
Mill is a proponent of hedonism (pleasure and the absence of pain are the ultimate intrinsic goods) within the ethical framework of utilitarianism. The core principle is the Greatest Happiness Principle: actions are right in proportion as they tend to promote happiness, wrong as they tend to produce the reverse of happiness. Happiness is considered for the greatest number of people possible. Mill also distinguished between higher (intellectual, moral) and lower (physical) pleasures.
Politics and Liberty
Individual liberty requires a society that values it. Individual freedom is a fundamental political good that should be preserved and maximized wherever possible, limited only by the Harm Principle (actions can be limited only if they cause harm to others). Democracy, particularly representative democracy, is seen as the most suitable system for protecting liberty. Key freedoms include:
- Freedom of Conscience: Absolute freedom of thought and feeling.
- Freedom of Expression: Near-absolute freedom to express opinions.
- Freedom of Action: Freedom to act as one pleases, provided it doesn’t harm others.
- Freedom of Association: Freedom to unite for any purpose not involving harm to others.
Mill proposed principles to guide state intervention:
- Principle of Subsidiarity (implied): The state should not undertake tasks that individuals or smaller groups can perform effectively.
- Principle of Individual Autonomy / Harm Principle: The state should only interfere with individual liberty to prevent harm to others.
- Principle of Civic Responsibility: Excessive state intervention can stifle individual initiative and civic responsibility.
- Principle of Citizen Participation: Encouraging citizen involvement in public affairs strengthens democracy and individual development.