I have just completed an introductory course in the philosophy of science. In it, the distinction was made between cause and explanation using the example of identities. So, for example, if we use the popular PSE statement "Water is H2O", then this explains what water is, but it does not say what causes two hydrogen atoms and an oxygen atom to be water.

The two concepts are obviously intimately related to one another. As relations they are both transitive, but neither symmetric nor reflexive.

Q: Other than identities, are there any examples that highlight this distinction?

TL/DR; At first I thought that fundamental principles may provide an example. E.g., Einstein's model explains gravity as the bending of space in the presence of mass, but it does not say what causes space to bend in the presence of mass. However, one could equally say that gravity is caused by the bending of space in the presence of mass without explaining why space bends in the presence of mass.

  • 2
    I apologize for not understanding several points in your question: 1) I would say "Water is H2O", changing the order of the words. I consider this neither an explanation, nor a cause, but a definition. 2) What causes two hydrogen-atoms and one oxygen-atom to combine to H2O? The electron shells of the participating atoms. What explains the combination: The theory of chemical bond. - What about the hypercycle of Manfred Eigen: Is it an example of symmetrical causation? What about the Christian concept of God as "causa sui": Is it an example of reflexive causation?
    – Jo Wehler
    Commented Dec 8, 2015 at 21:18
  • Many examples of reflexive, symmetric and transitive relations different from identity exist. Such relations are called equivalence relations. E.g. two sets are equivalent if a bijective map exists from one to the other. The resulting set of equivalence classes is named cardinal number.
    – Jo Wehler
    Commented Dec 8, 2015 at 21:24
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    @JoWehler My haste! Yes, "Water is H2O" is a much more natural statement of the fact (updated). I love your example of God as reflexive causation. I'm not familiar with Eigen's hypercycle, but I'll look it up. I would say that cause and explanation are neither reflexive nor symmetric because they do not hold for all x or all x and y, though, as you have noted, they do hold for some examples. The example of Water is H2O was one of the examples given in class. I read it as meaning the atomic explanation does not say what causes water to be wet and thirst quenching.
    – nwr
    Commented Dec 8, 2015 at 21:28
  • Concerning your example from physics: I do not consider gravity the explanation of the bending of light. Bending of light is explained by a theory, the General Theory of Relativity. In addition, I would not say that the curvature of space is the cause of gravity. Possibly one can say that gravity is(!) the metric field of spacetime, or less precise: gravity is the curvature of space. On the other hand - due to the field equations - one can say that mass, energy and pressure are the cause for the metric of spacetime, i.e. for gravity.
    – Jo Wehler
    Commented Dec 8, 2015 at 21:33
  • I assume that a smart chemist can derive from the theory of chemical bond that water is wet, i.e. is a liquid, under standard conditions. Hence she can indicate the cause :-)
    – Jo Wehler
    Commented Dec 8, 2015 at 21:39

5 Answers 5


What is the difference between cause and explanation?

Cause is a directed relation between two facts. Explanation is a directed relation between a theory and a fact.

Hence cause links two facts, i.e. two components of reality. While explanation links a set of propositions with a fact. Reality and the world of theories are two different ontological realms.

Added. Example: The moon and the sun cause tide on earth. Newton's theory of gravitation explains the phenomenon of tide on earth.

Added after comments:

Apparently I indicate only one essential difference between the two concepts, as far as both are relations. I do not state a definition of each term, which in case of cause would be a difficult and subtle task.

As an introduction to these further issues may serve Audi, Robert (Ed.): The Cambridge Dictionary of Philosophy. 1995. See the keywords causation and explanation.

  • I think that what your answer has taught me is that I am brining too much "folk" content to my thinking and I need to be more focused - in this case, on the scientific context.
    – nwr
    Commented Dec 8, 2015 at 22:05
  • I've accepted your answer because, although it does not provide examples, it does clearly answer the headline question.
    – nwr
    Commented Dec 9, 2015 at 15:26
  • Do you have a reference or source for these definitions, or are they your personal constructions? Commented Dec 10, 2015 at 13:13
  • @fileunderwater My answer did not intend to give definitions. I expanded my answer to clarify this intention and to give a reference for further investigation aiming at definitions.
    – Jo Wehler
    Commented Dec 10, 2015 at 15:25
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    @AgentSmith As far as I know there is no causal explanation which one of the atoms decays at which point of time. And quantum theory does not expect that there will be a causal explanation in the future.
    – Jo Wehler
    Commented Jan 10 at 5:50

An explanation is anything that answers a "why?" question. A causal explanation is a particuar kind of explanation that focuses on causes and effects. Questions like, "why are whales mammals?", "why is mercury liquid at room temperature?", "why does a match light when it is struck?" and "why did the chicken cross the road?" are all requests for explanations, but the answers will be of quite different kinds. These roughly correspond to Aristotle's four causes: formal, material, efficient and final. To Aristotle, explanation and cause amount to the same thing, but today we generally only use "cause" to refer to efficient causes.

There has been a fair amount of debate over the years as to whether causal explanations are fundamentally linked to scientific understanding of the properties of the universe (a position defended by Wesley Salmon), or whether explanation is principally epistemological in nature, i.e. it is concerned with how we organise our knowledge and how questions can be answered by reference to logical or probabilistic relationships within our knowledge (a position defended by van Fraassen).


According to Donald Davidson in "Actions, Reasons and Causes" for example, causes are a certain type of an explanation of a fact.

In this text he argues that it is a plausible story to be told to explain that there was a certain event. That is exactly the reason why he can state that reasons are in the very same sense causes of actions.

Hume said that causation is an inductive claim about the relation between two events that is not inferable from anything other than intuition (opposed to empiric facts).

For Kant in CPR, in Humean tradition, causation is a category, that means it is a modus of our synthesis of the manifold resulting in a certain intuition.

Hume and Kant, I would argue, do not really explain the event with its cause. They would not agree with Davidson. Explanation is telling a story about the genesis of an event. That is definitely more than naming a cause. But the similarities are that a certain form of inferential relation or framework is established between events.

To sum this up, my claim would be with Hume and Kant that causation is a direct, immidiate relation between two events that allows predictions, too, while explanation is used to establish a plausible relation between "historical" events that have had mediators. But of course, natural language uses causation in a broader, explanatory sense, too.

As a phenomenological fact, I might add, causation implicates a certain "teleological" direction from cause to effect, as Kant worked out (that's why there will never be a "Newton of a blade of grass" as he states in CoJ, because the relation between organism and organs are bilateral and we have no category for it, therefore cannot have proper perceptions ;). Explanation starts at the end, working backwards until the end is plausible.

  • I wanted to point out that while the identity is a matter of use in ordinary language as well as some philosophical positions such as Davidson's, I tend to your intuition that there is a difference. I like the answer of @JoWehler, too, but have no reference at hand to back it up.
    – Philip Klöcking
    Commented Dec 8, 2015 at 23:05

Causes are a kind of classification of explanations of how things have come about.

That water is H2O is an example of material cause - the explanation of what matter is used to bring something about, or make it.

To ask why it is that two hydrogen atoms together with an oxygen atom creates an atom of water, is a different question; it is asking how something has come about: it could be formal cause - in that it take two atoms of one, and one of another; or it could be efficient cause which is the 'primary source' of the change - one might say here, this is covalent bonding.

There is also a final cause, which refers to a purpose or end; for example, the final cause of Plato writing The Apology - is to defend Socrates against slurs and slander.

There are now well-developed bodies of knowledge ie science; then to ask for an explanation of a fact is to ask how that fact is explained by reference to some theory. One can then look closely at the explanation to classify its arguments by the above four-fold characterisation of causes.

In fact, there is a natural structure in this classification; when we consider a change, it has:

  1. a beginning state - and by reference to this we have an initial or efficient cause.

  2. And an end state - and by reference to this, we have a final cause

  3. and also a middle, which is the change itself; so forming and therefore formal cause.

  4. also there is something in that change which does not change - this is its matter - hence material cause.

This is, on the whole, Aristotles classification of causes; there are likely to be others.

  • Nice. It's always interesting to hear the classicist view.
    – nwr
    Commented Dec 9, 2015 at 6:00

Causes are types of explanations which determine a relation of priority and posteriority between the cause and the effect. In essence, a good distinction between cause and explanation is that something cannot cause itself, but something can explain itself. X can be X's explanans, but X cannot be X's cause. So, for example, when it is claimed that God is an uncaused cause, we are not thereby claiming that God is a brute fact, God still has an explanans, except that explanans is Himself, hence He is self-sufficient. One might, thus, claim that causes are types of explanations such that the explanans (cause) necessarily differs from the explanandum (effect), whilst explanations simpliciter dont require the explanans to differ from the explanandum.

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