Empiricism and Skepticism: A Study of Hume’s Philosophy
Hume
Historical Context
David Hume (1711-1776), born in Edinburgh, the son of a Scottish landowner, initially pursued business before turning to literature and philosophy. He studied at the University, focusing on Aristotelian logic and botany. He later moved to France, then the center of philosophical rationalism, where he wrote A Treatise of Human Nature. Returning to London to publish it, he met with complete failure. His fame grew later, even as his writings were considered subversive and heretical, challenging religious and moral doctrines. Despite several attempts, he was denied a university professorship. He retired to his homeland in 1769, where he lived until his death.
Hume is the foremost representative of empiricism, a philosophical movement with roots in the English Revolution of 1688. This period saw the triumph of political, religious, and economic freedoms, establishing England as a major commercial power and a model for parliamentary political systems. During the Enlightenment, the foundations of the old regime were criticized. Embracing reason, Hume sought to apply Newton’s scientific method to human nature, developing a new theory of knowledge that opposed Cartesian rationalism. He argued that experience is both the origin and limit of our knowledge. His radical empiricism critiqued traditional Platonic-Aristotelian metaphysics and modern philosophy. He questioned established ideas about causality and the universe.
Hume’s skepticism led him to doubt everything, viewing phenomena as isolated occurrences without universal or necessary connections. He reduced reality to mere perceptions, ultimately leading to a skepticism that “emptied philosophy of its contents.”
Theory of Knowledge
Descartes, a representative of rationalism, prioritized reason over sensory data. He believed that experience was worthless without rational order and a rigorous method (methodological doubt, rules) leading to clear and true thinking. For Descartes, an idea is a mental act, independent of what it represents. He advocated nativism, proposing three innate ideas (self, God, and the world) as the basis for understanding external reality through the attributes of res extensa (extended substance) and res cogitans (thinking substance), including movement and its modes or accidents.
In contrast, Hume argued that all knowledge originates from experience, which serves as both its source and limitation. He believed that reason alone is insufficient. All materials of the human mind, everything we perceive, are composed of impressions and ideas derived from sensory data. Hume’s concept of an idea is a copy or derivative of a sensory impression. Unlike Descartes, Hume did not view ideas as separate entities. Thought, for Hume, consists of mental images derived from impressions, as there is no direct contact between the mind and objects. He divided knowledge into two types:
- Relations of Ideas: Derived through demonstrative arguments, these are self-evident, necessary, and always true. Examples include geometry, algebra, and arithmetic (e.g., the whole is greater than the parts).
- Matters of Fact: Encompassing most of reality, these are never necessary and are derived through probable reasoning. Causality is central to our understanding of matters of fact, but Hume denies the validity of causal inferences.
Hume distinguished between simple and complex impressions, as well as impressions of sensation (external experience) and impressions of reflection (internal experience). Simple ideas arise from simple impressions, while complex ideas arise from the association of simple ideas. Imagination plays a crucial role, as complex ideas, such as causality, may lack a real basis in experience.
Hume saw no need to justify induction due to the role of experience in his thinking. He employed the concept of reason in two ways: empirical and deductive. Empirical reason refers to experience-based reasoning. Deductive reason, while valid, must be connected to experience. He rejected the purely deductive ideal of continental rationalism, arguing that it lacked empirical grounding.
The Idea of Substance
Descartes defined substance as that which has the cause of its existence within itself. He distinguished between an absolute substance (God) and two finite substances: res extensa and res cogitans. These independent substances possess attributes and modes, features that depend on the substance. This radical dualism led to the problem of how humans, who are both thought and extension (body and soul), can be unified. Descartes explained bodily movement through its material composition and attributed intellect, will, and freedom to the soul.
Hume criticized and rejected the concept of substance, viewing it as an innate idea lacking any basis in impression. We have impressions of qualities, but not of a “substance” underlying them. He argued that the belief in substance is based on custom.
Regarding the soul, Hume argued that since we only know particular qualities and perceptions, we have no impression of a self or a substance, whether material or spiritual. The soul is not a substance or a defined object knowable through impressions.
God
Descartes defended the existence of God as one of the three innate ideas, bridging the gap between self and world, res extensa and res cogitans. His arguments included the ontological argument and the argument from causality. He supported a limited natural religion based on reason.
Hume denied the existence of God due to the lack of any corresponding impression. He rejected natural religion and deism, arguing that religion arises from feeling (fear, doubt, ignorance), not reason. He proposed a natural history of religion based on social utility (peace, good works).
Ethics
Descartes argued that the soul’s task is to govern the passions (involuntary, immediate, and not always rational). Reason reveals the good, providing the basis for moral judgments. As res cogitans, the self possesses free will, allowing us to choose what reason proposes as good and true.
Hume, in his project of a science of man, denied the role of reason in ethics. He argued that our actions are determined by our knowledge of ideas or facts. Moral judgments are based on the consistency of human behavior with the natural order, but these judgments are grounded in sentiment (approbation or disapproval), not reason. Hume grounded consciousness and the self in emotions, arguing that human will is closely tied to passions, which are impressions derived from facts.