What is the extent to which we are dependent upon experience in gaining knowledge of the external world?

Experience has two kinds:

  1. Sense experience - five senses; acquires knowledge of external objects
  2. Reflective experience - includes conscious awareness of our mental operations; acquires knowledge of our minds

The distinction between sense and reflective experience is often neglected in the rationalism vs. empiricism dispute.

Rationalists criticize empiricists for claiming that all ideas originate from sense experience.

Rationalists claim that we can gain knowledge independent of sense experience.

Rationalists do not have to believe that knowledge is acquired independent of any experience. For one, rationalists believe that reflective experience (i.e., conscious awareness of thought) is necessary for reasoning.

Rationalists develop their view in two steps:

  1. There are cases where the content of our concepts or knowledge outstrips the information that sense experience can provide.
  2. Reason provides additional information about the external world.

Empiricists develop their view in two steps:

  1. Experience alone provides the information that rationalists cite because we have it in the first place.
  2. Reflective understanding can and usually supplies the missing links in our concepts or knowledge.
  • For example, Locke’s said that the idea of substance is a composite idea that incorporates both sensation and reflection.

Almost no author is a pure rationalist or a pure empiricist.

  • For example, although Descartes is a hardcore rationalist in metaphysics, he was empiricist in natural philosophy, where sense experience plays a curcial role.
  • Locke, although an empiricist, argued that reason is as important as experience when it comes to knowledge of moral truths.

Rationalism vs. empiricism is an epistemological issue.

Knowledge is divided into three categories:

  1. Knowledge of the external world
  2. Knowledge of the internal world or self-knowledge
  3. Knowledge of moral and/or aesthetical values

Some defining questions of epistemology related to the rationalism vs. empiricism dispute are the following:

  1. What is the nature of propositional knowledge, knowledge that a particular proposition about the world, ourselves, morality, or beauty is true?
  • To know a proposition it must be true and warranted (which means it is not a lucky guess).
  1. How can we gain knowledge?
  • We can make lucky guesses or warranted beliefs. We must be able to think about the object of our knowledge. How do we gain our concepts? Is the way we divide the world in concepts accurate?
  1. What are the limits of our knowledge?
  • We could think about some things but not have knowledge about them (e.g., competing descriptions about a certain thing, make us not know what to believe in).
  • Some things may be beyond the limits of thought. We cannot form intelligible descriptions of them. Even if we make an intelligible description, we cannot know if it is true. A very good example of this will be the platonic realm.

Rationalism vs. empiricism is primarily about the sources of our concepts and knowledge. But it can incorporate the nature of warrant and the limits of thought and knowledge.

How can we gain knowledge?

There are three main theses:

  1. Intuition/Deduction Thesis
  2. Innate Knowledge Thesis
  3. Innate Concept Thesis

Intuition/Deduction Thesis: “Some propositions in a particular subject area, S, are knowable by us by intuition alone; still others are knowable by being deduced from intuited propositions.”

We can generate different versions of the Intuition/Deduction thesis by substituting different subject areas for the variable ‘S’.

This has been traditionally seen as what distinguished rationalism from empiricism. However, rationalists and empiricists now agree with this thesis.


  • A form of direct, immediate insight.
  • An internal perception
  • We intellectually grasp a proposition and just “see” it to be true, forming a true, warranted belief in it. However, the nature of this “seeing” needs explanation.


  • A process in which we derive conclusions from intuited premises through valid arguments, ones in which the conclusion must be true if the premises are true.

Intuition and deduction provide us with knowledge that is independent, for its justification, of experience. This is called “a priori” knowledge.

Innate Knowledge Thesis: “We have knowledge of some truths in a particular subject area, S, as part of our nature.”

We get different versions of the Innate Knowledge thesis by substituting different subject areas for the variable ‘S’.

According to this thesis, there are certain knowledge that comes from our nature. We are born with it. Its justificiation does not depend on experience or intuition/deduction. Experiences could bring these knowledge to consciousness but not provide the knowledge themselves. We may have gained this knowledge from an earlier existence, from God, or through natural selection.

Empiricists reject the innate knowledge thesis. According to them, even if such knowledge existed, it would be little use to us.

Innate Concept Thesis: We have some of the concepts we employ in a particular subject area, S, as part of our rational nature.

According to this thesis, sense experiences may trigger a process that brings these concepts to our concsiousness, but experience do not provide the concepts or the information they contain. The concepts are part of our rational nature.

Some believe that the Innate Concept thesis is entailed by the Innate Knwledge thesis: knowledge can only be innate if the concepts in the proposition are also innate.

The more a concept is removed from experience and mental operations we can perforn on experience, the more plausibly that it is innate. For example, we do not exprience a triangle, so our concept of it is more innate. On the other hand, we experience pain. So our conceot of it is less innate.

The Intuition/Deduction thesis, the Innate Knowledge thesis, and the Innate Concept thesis are essential to rationalism.

To be a rationalist is to adopt at least one of them: either the Innate Knowledge thesis, regarding our presumed propositional innate knowledge, or the Innate Concept thesis, regarding our supposed innate knowledge of concepts.

Rationalists vary the strength of their view by adjusting their understanding of warrant.

  1. Warranted beliefs are absolute truths and intution provides them.
  2. Warranted beliefs are beyond reasonable doubt and intution provides them.

Some ratonalists believe that intuition is infallible. Others believe intuition can be false.

Two theses are generaly adopted by rationalists (but you can still be a rationalist without believing them):

  1. The Indespensability of Reason Thesis: The knowledge we gain in subject area, S, by intuition and deduction, as well as the ideas and instances of knowledge in S that are innate to us, could not have been gained by us through sense experience. → Sense experience cannot provide what we gain from reason.
  2. The Superiority of Reason Thesis: The knowledge we gain in subject area S by intuition and deduction or have innately is superior to any knowledge gained by sense experience.

How is reason superior to experience?

  1. What we know by intuition is certain, beyond even the slightest doubt, while what we believe, or even know, on the basis of sense experience is at least somewhat uncertain.
  2. What we know by reason alone is superior in an important metaphysical way to what we are aware of through sense experience.

Some commitments that rationalists make:

  1. Some rationalists are committed to denying scepticism on truths they know by intuition, deduction, or innate knowledge.
  2. Rationalists who believe in the Intuition/Deduction thesis are also committed to epistemic foundationalism—the belief that certain truths are absolute and we can use them as foundational knowledge to know more truths (this is Steve Patterson’s belief).

Empiricists also believe in the Intuition/Deduction thesis but they only on the contents of our mind and not empirical facts from the external world.

Empiricists reject the Innate Knowledge and Innate Concept theses.

Empiricists believe that all knowledge are gained, not just triggered, by sensorial or reflective experience.

Experience is our only source of ideas.

Empiricists reject the Superiority of Reason thesis. Since reason alone cannot give us knowledge, it certainly does not give us superior knowledge.

Empiricists need not reject the Indispensability of Reason thesis, but most of them do.

The Empiricism Thesis: We have no source of knowledge in S or for the concepts we use in S other than experience.

The Empiricism Thesis does not entail that we have empirical knowledge but that we can only gain knowledge by experience.

The basic claims of rationalism and empiricism are relative to a particular subject area. This means that rationalism and empiricism, when relativized, need not conflict.

Rationalism and empiricism only conflict when formulated to cover the same subject.

The distinction between rationalism and empiricism does not mean that there are no longer other sources of knowledge. We can be either a rationalist and empiricist yet still believe that knowledge in a particular area can come from Divine revelation, which is not a product of either reason or sense experience.

We have to be careful of the rationalist and empiricist labels because using them the wrong way could impede our understanding.

This distinction, initially applied by Kant, is responsible for giving us a very restrictive philosophical canon, which does not take into account developments in the philosophy of emotions, philosophy of education, and even disputes in areas of philosophy considered more mainstream, like ethics and aesthetics.

Unless restricted to debates regarding the possibility of innate knowledge, this distinction is best left unused.

The best debate between rationalism and empiricism is about truths about the external world.

The rationalist position about knowledge of the external world is that some are and must be innate and that this knowledge is superior to any that sense experience could ever provide.

The empiricist position about knowledge of the external world is that experience is their sole source. Reason can inform us about the relations among truths about the external world, but those truths can only be gained through experience.

Historically, the rationalist/empiricist dispute in epistemology has extended into the area of metaphysics.

Some rationalists present metaphysical theories, which they claim to have known by intuition and/or deduction alone. Empiricists reject these theories as speculation beyond what we can learn from experience, or nonsensical attempts to describe aspects of the world beyond the concepts experience can provide.

The rationalist-empiricist debate even questions the very need for metaphysics. Metaphysics can only be an area of human knowledge through a resolution of the rationalist and empiricist debate.


Markie, P., & Folescu, M. (2021). Rationalism vs. Empiricism. In E. N. Zalta (Ed.), The Stanford Encyclopedia of Philosophy (Fall 2021). Metaphysics Research Lab, Stanford University. https://plato.stanford.edu/archives/fall2021/entries/rationalism-empiricism/