Introduction
Empiricism is the epistemological theory that all knowledge is derived from sensory experience. Opposing the Rationalist belief in innate ideas, the British Empiricists of the 17th and 18th centuries—John Locke, George Berkeley, and David Hume—argued that the human mind at birth is a tabula rasa or “blank slate.” Every concept we have, no matter how abstract, can ultimately be traced back to impressions gathered through our five senses.
This “bottom-up” approach to knowledge laid the groundwork for the modern scientific method, emphasizing observation, experimentation, and evidence over abstract speculation.
Key Arguments for Empiricism
1. John Locke and the Tabula Rasa
In his An Essay Concerning Human Understanding, Locke famously argued against “innate principles.” He claimed that if there were innate ideas (like the idea of God or the law of non-contradiction), then everyone would possess them. Yet, he noted, children and people from different cultures do not share a common set of “universal” ideas.
Locke divided ideas into two types:
- Simple Ideas: The building blocks of thought received through sensation (e.g., the “coldness” or “hardness” of an ice cube).
- Complex Ideas: Created by the mind through comparing, combining, and abstracting simple ideas (e.g., the concept of a “universe”).
2. Primary and Secondary Qualities
Locke distinguished between properties that exist in objects themselves (Primary Qualities like extension, figure, and motion) and properties that only exist in our perception of those objects (Secondary Qualities like color, sound, and taste). A rose is physically shaped in a certain way, but its “redness” is a sensation produced in us by the way its atoms interact with our eyes.
3. David Hume and the “Copy Principle”
David Hume took empiricism to its logical (and more radical) conclusion. He distinguished between Impressions (vivid sensory experiences) and Ideas (faint copies of impressions used in thinking). According to Hume’s “Copy Principle,” we cannot have an idea of something unless we have first had a corresponding impression. If you try to imagine a “new” color that you have never seen, you will find it impossible.
The Empiricist Spectrum
- Locke (Representative Realism): Believed that an external world exists, but we only know it through the ideas it creates in our minds.
- Berkeley (Idealism): Argued that “to be is to be perceived” (esse est percipi). He claimed that secondary qualities and primary qualities are just ideas. Therefore, matter does not exist; only minds and their ideas exist.
- Hume (Skepticism): Argued that even our most basic beliefs, such as the principle of Cause and Effect, are not justified by reason. We see event A (fire) followed by event B (smoke) many times, and our minds form a “habit” of association. But we never actually see the “power” or “necessity” that connects them.
Critiques of Empiricism
- The Problem of Induction: Hume himself pointed out that we cannot justify the belief that the future will resemble the past (induction) based on experience, because that would be circular reasoning.
- The Role of the Mind: Immanuel Kant (who sought to synthesize the two schools) argued that the mind is not just a passive slate. It must have internal “categories” (like time, space, and causality) that organize sensory data into meaningful experience.
- Abstract Entities: How does empiricism explain our knowledge of numbers or logical laws? We can see three apples, but can we see the number three itself? Rationalists argue that such concepts require a non-sensory faculty.
Modern Context
Empiricism is the bedrock of modern Naturalism and the Scientific Method. The insistence that theories must be “falsifiable” and supported by repeatable data is a direct descendant of the empiricist tradition.
In psychology, the Behaviorist movement of the 20th century (Watson and Skinner) was a radical form of empiricism, suggesting that all behavior is a result of environmental conditioning rather than internal mental states. In the tech world, the rise of Machine Learning and “Big Data” represents a triumph of empirical methods: instead of “teaching” a computer the rules of language (rationalism), we give it billions of examples and let it find the patterns through experience (empiricism).
However, the “Rationalist vs. Empiricist” debate continues. As we explore the limits of knowledge in the next lesson, we will see how the radical implications of empiricism led David Hume toward a profound and disturbing Skepticism.