Locke believes that humans obtain all ideas by experience (of the environment). In other words, he believes that humans are born a blank slate (tabula rasa) without ideas. Locke is recognized as one of the founding fathers of British empiricism, which stands in stark contrast with continental rationalism.
Counterarguments against innate ideas
Locke counters some arguments for the existence of innate ideas:
- Some ideas enjoy universal assent, i.e. everyone agrees the idea is true. Descartes’ example is “something can’t be and not be simultaneously.”
- Descartes disagrees because because babies can’t agree—they don’t have the capability of understanding or thinking about them yet.
- However, it is not clear whether innate ideas are the only reason for universal assent.
- Some ideas would hypothetically enjoy universal assent by rational persons. Once they’ve heard of them they would agree.
- Descartes’s counter:
- The idea doesn’t have to be innate for humans to agree with it. Humans have reason—it could very well be that a person heard of the idea, analyzed the idea with reason, and eventually agreed.
- Descartes’s counter:
Theory of Ideas
Locke believes that are two types of ideas:
- Sensation, which is obtained from sensory organs observing external objects.
- Reflection, which is obtained from the mind reflecting about its own internal states. Descartes believe the emergence of reflection only comes after children have had ample sensations.
Locke argues that all ideas come from sensations or reflections. There is no other way of obtaining knowledge of simple ideas other than to experience them—a blind person cannot imagine what colors are like. In addition, complex ideas are just compositions of simpler sensations or reflections.