Reading Time: 10 minutes By Joreth (Own work) [CC BY-SA 3.0 (], via Wikimedia Commons
Reading Time: 10 minutes

Having posted the Philpapers survey results, the biggest ever survey of philosophers conducted in 2009, several readers were not aware of it (the reason for re-communicating it) and were unsure as to what some of the questions meant. I offered to do a series on them, so here it is – Philosophy 101 (Philpapers induced). I will go down the questions in order. I will explain the terms and the question, whilst also giving some context within the discipline of Philosophy of Religion.

This is the ninth post, after

#1 – a priori

#2 – Abstract objects – Platonism or nominalism?

#3 – Aesthetic value: objective or subjective

#4 – Analytic-Synthetic Distinction

#5 – Epistemic justification: internalism or externalism?

#6  – External world: idealism, skepticism, or non-skeptical realism?

#7 – Free will: compatibilism, libertarianism, or no free will?

#8 – Philosophy 101 (philpapers induced) #8: Belief in God: theism or atheism?

#9 – Philosophy 101 (philpapers induced) #9: Knowledge claims: contextualism, relativism, or invariantism?

The question for this post is: Knowledge: empiricism or rationalism? Here are the results:

Other 346 / 931 (37.2%)
Accept or lean toward: empiricism 326 / 931 (35.0%)
Accept or lean toward: rationalism 259 / 931 (27.8%)

First thing to note is a fairly even split, with “Other” featuring prominently, though with empiricism having the edge over rationalism by some 10%.

The other thing to notice is that the last question featured the term “knowledge claims” whereas this one just talks about “knowledge”.

I see this as talking about systems we use to gain further knowledge, as well as propositional knowledge, and we are not a million miles away from a previous topic of “a priori” – can we have knowledge a priori, or before the fact (from the earlier) – in other words, before we use our senses to check out empirically what is going on?

In some sense, this is a simple rephrasing of that debate.


The Stanford Encyclopedia of Philosophy states that rationalists adopt at least one of three statements:

The 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.

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

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

We either know things to be true intuitively, or as part of being rational agents, or the empirical may trigger concepts already embedded within our nature. Of course, one weakness here is in establishing what intuition actually is.

Whilst other ideas and theses are closely connected to rationalism, or are often associated with it, I will keep it simple by only involving the above three.

One question that is often touted about such rationalism is the epistemic warrant: if someone uses intuition about a certain proposition, then it can be seen as lacking reason, and is thus potentially less justifiable, lacking in being warranted. How does an intuitive claim become a warranted claim?


For the empiricist, the following must be true in some way:

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

The source of knowledge for us is claimed to be a posteriori (from the latter) in its entirety, at source. Things may become intuitive, and even lacking reason, but they are as a result of us using our senses over time to formulate our propositional knowledge, and our systems that we use to navigate through the world. As the SEP continues:

Empiricism about a particular subject rejects the corresponding version of the Intuition/Deduction thesis and Innate Knowledge thesis. Insofar as we have knowledge in the subject, our knowledge is a posteriori, dependent upon sense experience. Empiricists also deny the implication of the corresponding Innate Concept thesis that we have innate ideas in the subject area. Sense experience is our only source of ideas. They reject the corresponding version of the Superiority of Reason thesis. Since reason alone does not give us any knowledge, it certainly does not give us superior knowledge. Empiricists generally reject the Indispensability of Reason thesis, though they need not. The Empiricism thesis does not entail that we have empirical knowledge. It entails that knowledge can only be gained, if at all, by experience. Empiricists may assert, as some do for some subjects, that the rationalists are correct to claim that experience cannot give us knowledge. The conclusion they draw from this rationalist lesson is that we do not know at all.

The Debate

The simple fact is that, and I assume this is why there is a large “Other”, many philosophers actually advocate for both, and others are skeptics, such that knowledge is not possible, or do not claim that it is possible. For example, on the former point, you could be rationalist about maths and mathematical claims, but empiricist about physical sciences. When, however, the domain being analysed has a crossover of empiricism and rationalism, we might have more of a problem. This can present problems when defining historical philosophers as entirely rationalist or empiricist, where a more nuanced approach is advised.

Nonetheless, an important debate properly described as ‘Rationalism vs. Empiricism’ is joined whenever the claims for each view are formulated to cover the same subject. What is perhaps the most interesting form of the debate occurs when we take the relevant subject to be truths about the external world, the world beyond our own minds. A full-fledged rationalist with regard to our knowledge of the external world holds that some external world truths can and must be known a priori, that some of the ideas required for that knowledge are and must be innate, and that this knowledge is superior to any that experience could ever provide. The full-fledged empiricist about our knowledge of the external world replies that, when it comes to the nature of the world beyond our own minds, experience is our sole source of information. Reason might inform us of the relations among our ideas, but those ideas themselves can only be gained, and any truths about the external reality they represent can only be known, on the basis of sense experience. This debate concerning our knowledge of the external world will generally be our main focus in what follows.

A thought experiment that I always find useful is imagining a disembodied mind at birth, if you will. Can you see that mind ever taking in more knowledge without any sensory input whatsoever? Can it access rational or non-empirical knowledge without recourse to any senses at all? And are rational sources of knowledge actually found within neural networks?

As a naturalist, and this is a pretty important point, I believe that the mind is supervenient on the physical matter of my brain and body. So at this source level, with the mind being at worst reflective of the physical brain, but certainly dependent on it, we have an issue for rationalism. Intuitive feelings or claims are still resultant from neurons firing and physical substrates and interactions within the body and brain. How does this affect the debate? If rationalism is the result of biological evolution and neural networks, what does this say about rationalism? Does it, in some manner, now become a sort of empiricism, or just because the innateness is sourced in biological systems, can we not still define something as rationalist?

AJ Ayers said of rationalism:

There can be no a priori knowledge of reality. For … the truths of pure reason, the propositions which we know to be valid independently of all experience, are so only in virtue of their lack of factual content … [By contrast] empirical propositions are one and all hypotheses which may be confirmed or discredited in actual sense experience. [Ayer 1952, pp. 86; 93–94]

As mentioned earlier, what is intuition? How can it support a warranted belief? “Grasping” or “seeing” things is simply not good enough, arguably, in establishing epistemic warrant, and some will also claim (see David Eagleman’s Incognito for some interesting examples of intuition) that these intuitions are often actually previously embedded, nonconsciously experienced, phenomena. Knowledge, according to pragmatists, is only knowledge when it is reliable, and how can you test intuition without recourse to the external world in validating its reliability? As the SEP continues:

What accounts for the reliability of our intuitions regarding the external world? Is our intuition of a particular true proposition the outcome of some causal interaction between ourselves and some aspect of the world? What aspect? What is the nature of this causal interaction? That the number three is prime does not appear to cause anything, let alone our intuition that it is prime.

It is true that we can never be certain about the external world. We could be living in The Matrix – there is always some non-zero element of doubt in any proposition. In a sense, that is the nature of empiricism: probabilities. But all reasoning is grounded using the Munchausen Trilemma, either in:

  • infinite regress
  • circular reasoning
  • an axiom

And, some might say, the soundest of the three is the axiom, as self-evident truth (though some don’t have a problem with circularity in principle). If you can’t give derivative reasons as to why something is true (i.e., that I am not in The Matrix), and can’t rely on empirical data, then where does this leave us? Perhaps we have to admit that there is no justifiable reason as to why we are not in The Matrix. However, this might be a neutral claim, since you could say that there is no justifiable reason as to why we are.

Certainly, self-evident truths are something that okay into rationalist hands. Merely just understanding what such a claim says is enough for us to think it is true.

The idea that we have innate knowledge is, to me, problematic, given the disembodied mind hypothesis above. Knowledge flows out incrementally from brain development that goes hand in hand with knowledge acquisition. We learn. We are always learning, and this learning is done through taking things in from the outside world into our senses.

Language us interesting as it appears to rest in some sense on grammar and syntax, which can be seen as a sort of logic. Is logic innate? Is the Law of Non-Contradiction something that is rationally in-built? Or does it come from making sense of data? If I see something is blue, then it is blue and not red. My senses lead me to understand that it cannot be both. But is that understanding innate? But we surely need to be able to test the law against real, observed examples. So at best for the rationalist, the law is empirically warranted.

The SEP says of Noam Chomsky, famous scholar of language (and many other things):

It is important to note that Chomsky’s language learners do not know particular propositions describing a universal grammar. They have a set of innate capacities or dispositions which enable and determine their language development. Chomsky gives us a theory of innate learning capacities or structures rather than a theory of innate knowledge. His view does not support the Innate Knowledge thesis as rationalists have traditionally understood it. As one commentator puts it, “Chomsky’s principles … are innate neither in the sense that we are explicitly aware of them, nor in the sense that we have a disposition to recognize their truth as obvious under appropriate circumstances. And hence it is by no means clear that Chomsky is correct in seeing his theory as following the traditional rationalist account of the acquisition of knowledge” (Cottingham 1984, p. 124).

Establishing warrant for any kind of innate knowledge is very difficult, and usually defers, again, to some sort of reliabilism, which is very difficult to establish without recourse to taking in empirical data. So even if you have a piece of innate knowledge, to make it warranted and to test its reliability, you need empiricism.

Of course, metaphysics is arguably the bedrock of rationalist thought.

But taking something like morality, would I have a coherent idea of morality if I had never seen other agents be kind or unkind? If I had never experienced morality, and empathised with others, would I ever have had access to moral knowledge? I think not.

When we see causation at play, we are using inference from all the other instances of causation that have taken place and experienced in our lives. We then apply these experiences to the new event. We might appear to be being intuitive, but our senses have been sifting through billions of pieces of data since our births.

Does a blind person have a concept of redness? Of chairness? imagine a blind person had no sense of feeling, would they have innate knowledge of the things around them? We get back to a version of the disembodied mind.

Maths can create much debate, too. 2 + 2 = 4 is arguably innate. But, the empiricist might say, you first learnt this from seeing multiple objects and counting them. True, but this is the source of learning the maths, not the source of the truth. And this can be applied to many of the previous claims concerning the brain.

We could derail here to get on to abstract objects and mathematical Platonism. Maths is, to me anyway, a descriptive language of reality, not reality. There is no ontic reality to the abstract maths we do, which we do to better understand the world out there.

How this might pertain to God

Rationalists like Descartes have used pure reason and rationalist approaches to argue for the existence of God. Descartes started by stripping back knowledge to the indubitable – knowing that the thinking entity exists. But is even that a result of sensation, in some manner? If the mind supervenes, depends upon, the physical, what does it say about that kind of Cartesian conclusion? Descartes had a fundamentally faulty understanding of physiology and the brain, let alone what the mind might be.

Descartes believed that we had an innate concept of God, as the SEP elucidates:

Consider Descartes’s argument that our concept of God, as an infinitely perfect being, is innate. Our concept of God is not directly gained in experience, as particular tastes, sensations and mental images might be. Its content is beyond what we could ever construct by applying available mental operations to what experience directly provides. From experience, we can gain the concept of a being with finite amounts of various perfections, one, for example, that is finitely knowledgeable, powerful and good. We cannot however move from these empirical concepts to the concept of a being of infinite perfection. (“I must not think that, just as my conceptions of rest and darkness are arrived at by negating movement and light, so my perception of the infinite is arrived at not by means of a true idea but by merely negating the finite,” Third Meditation, p. 94.) Descartes supplements this argument by another. Not only is the content of our concept of God beyond what experience can provide, the concept is a prerequisite for our employment of the concept of finite perfection gained from experience. (“My perception of the infinite, that is God, is in some way prior to my perception of the finite, that is myself. For how could I understand that I doubted or desired—that is lacked something—and that I was not wholly perfect, unless there were in me some idea of a more perfect being which enabled me to recognize my own defects by comparison,” Third Meditation, p. 94).

The problem here being that our concept of God can be seen in terms of human psychology, and is built up out of other concepts. In more pagan and polytheistic religions, they are human or animalistic, and have flawed personal attributes. In Judeo-Christian monotheism, God still looked like just a very powerful man. Patternicity, our desire to live forever and cope with death, the justification for our moral proclamations: all of these sorts of things are why God was invented. I do not think God as an innate concept is remotely defensible given that it seems derived from aspects of the world around us.

Here’s another thing. My twin six-year-old boys have no concept of God. I have not taught it to them. I have, on occasion due to mention in a film, sort of explained deities, but they appear to have no innate concept of God. Empirically from my own experience of my boys, this claim of innateness does not hold. Now, society is geared up towards thoughts and concepts of deities, and they will no doubt interact with these in due course. The prevalence of belief and religion is more about the psychological function that such beliefs provide.


Well, tough one. I think, for me at any rate, it doesn’t really matter. Yes, rationalism might hold for certain interpretations of maths, and perhaps for logic. But without empiricism, it’s all useless. I prefer a pragmatic and reliabilist approach in that justification needs sensory data and empiricism; and to show something as reliably and usefully true, you need to test it on the outside world. I think, therefore I am. This may be the bedrock of epistemological claims, but it doesn’t really get you anywhere else useful.

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Jonathan MS Pearce

A TIPPLING PHILOSOPHER Jonathan MS Pearce is a philosopher, author, columnist, and public speaker with an interest in writing about almost anything, from skepticism to science, politics, and morality,...