Preface: I know that 'positive' means the acceptation in philosophy of "dealing only with facts".

[Source: 80% down the page:] Should we instead just decree that knowledge is justified true belief provided that, additionally, there is no element of luck involved? This is an odd suggestion for several reasons. First it would be odd to have a negative criterion in the definition of knowledge. There not being any luck involved[,] is not some thing[.]
[T]hat is, [the lack of luck is] an absence of a thing. Or [to wit, this lack of luck is] a nothing[.]
A nothing or non-thing cannot be a cause of something positive.
What doesn't have any being as a thing[,] cannot explain why someone knows something if knowing something is something positive.

I do not comprehend how the bold is true, even for epistemology.

For example, suppose that I lack knowledge of epistemology. Then this lack would inspire me to learn about epistemology, after which I will have gained truly positive knowledge.
So does my example attest that absence of something can generate something positive?

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    I cannot see the page, as it requires an account to log in. But the usage of "positive" and "negative" in the excerpt follows the jargon of equating "positive" with "some being" and "negative" with "no being", hence it would simply rest on a definitional or perhaps conventional basis. As for your example, lack of knowledge about some particular thing might be distinguished from lack of knowledge about nothingness in that the first is at least possible. And an alternative to your negative knowledge of philosophy causing you to be drawn to it could be your own natural positive drive towards it.
    – ejQhZ
    Dec 21, 2015 at 8:28
  • @ejQhZ +1. Thanks. Can you please explain As for your example, lack of knowledge about some particular thing might be distinguished from lack of knowledge about nothingness in that the first is at least possible.? Why is the latter impossible? Please advise whether I should post a new question about this, if the answer shall be long.
    – user8572
    Jan 3, 2016 at 21:46
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    I realize now that my comment might have been ambiguous. What I referred to as "impossible" was "knowledge about nothingness", and I did so on the basis that knowledge must refer to something (or that "whatever can be thought of or spoken of is"). Furthemore, even if it were possible, what could possibly be missing in it, such that someone might "lack knowledge of nothingness"? But if you find these ideas aren't without problems, then I advise you do make a new question.
    – ejQhZ
    Jan 12, 2016 at 18:08

6 Answers 6


Kant argued, as a critical blow to the Ontological Argument for the Existence of God, that existence cannot be described in terms of being a predicate. In other words, a thing does not have the property (or a lack thereof) of existence, and instead, 'existence' is merely the term that we apply to concepts that are exemplified in the real world. It makes no sense to claim that an item does not exist, while still maintaining that it has the ability to be one of the four Aristotelian causes. Without it actually existing, it is merely a concept, and concepts do cause physical effects.

As for your interesting example, it is not the lack of understanding that is causing you to learn, but rather your desire and ability to rid the 'lack of understanding', so to speak. My mother, for example, is a dentist with essentially zero interest in epistemology, but a passion for dentistry. My lack of knowledge of dentistry, and her lack of knowledge of epistemology, do not compel us to learn one another's interests, as you seem to have implied, intentionally or otherwise.

Of course, the causal relationship that you propose has many assumptions that can be easily violated. For example, if you don't have access to information regarding epistemology, or you had never learned to read, or had a neurological disorder rendering any learning temporary or impossible. None of these things, however, are causing any positive event or change to occur.

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    +1. Thanks. Is the last sentence in your 1st paragraph perfect and intended? Is a 'not' missing: it is merely a concept, and concepts do [NOT] cause physical effects. ?
    – user8572
    Jan 14, 2016 at 16:30

In the physical sciences especially, we commonly think of causes and effects as being facets of events. A brick hits a window (an event) and this causes the window to smash (another event, caused by the first). In this sense, one could hardly say that the absence of something could be a cause, because the absence of something is not an event.

But in ordinary speech we use the language of cause and effect to describe actions, situations and motivations that relate to people and by extension to the things people make. In this sense, causes and effects are rather more diverse in nature, and some might be purely negative. For example, if I ask, "Why doesn't my car start?" (i.e. what is the cause of my car failing to start) the answer might be: because there is an absence of fuel in the tank. It is not an event that is the cause of my car not starting but an absence of something that one would normally expect to find. Or again, "Why did this machine break down?" (i.e. what caused it to break down) might elicit the response: because the operator had not been trained and did not know how to operate it correctly (i.e. an absence of the required skill).

Often when we speak of causes in the context of humans and human artefacts we work from a model of what we consider normal and identify the cause as the deviation from normality. So if an aircraft crashes and we enquire what caused it, we don't give the useless answer: gravity, which is part of the normal operating conditions of an aircraft, but pilot error, or birdstrike, or component failure, etc. This deviation from normality could be positive or negative in general.

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    How dou you reconcile the two?
    – nir
    Jan 4, 2016 at 4:03
  • I'm not entirely sure. Some philosophers speak of a different species of causation called "agent causation" - often this concept is introduced in the context of discussions of the free-will problem. But whether agent causation is reducible to event causation, or even supervenient upon it, is not clear.
    – Bumble
    Jan 4, 2016 at 6:36

Because "causality" is a word, we can define it to have any convenient properties we please.

In particular, this definition prohibiting nothing or non-things from causing an event avoids a particularly frustrating explosion of non-things that we can come up with to cause an event.

By defining it this way we define the concept of causation to only be valid for things. If we were to perceive "nothingness" as causing something to occur, we are encouraged to reframe the problem such that the cause can be something that exists (quite often that something is part of our "self")


I agree with your objection. The notion as stated is logically false, but it captures a true intuition in principle.

Here is a clearer objection: The emptiness of space is the cause of all energy. We can conceive of the space with or without the energy. But if all of space were somehow truly full in every way, we would have a solid, motionless universe permanently and necessarily frozen at absolute zero, because nothing could move.

Obviously, from a purely linguistic point of view, the presence of one thing is the absence of its exact opposite. So you can always flip negatives into positives and "A nothing or non-thing cannot be a cause of something positive", on its face, makes no sense.

Fairness or equality is the relevant opposite of luck, here. So from a completely logical point of view you could just say 'knowledge is justified true belief if it would continue to be justified and believed were the access to all information fair and equal'. Then we would mean the same thing, with no negative or absence.

However, there is still a weakness here. One would not logically ever consider the notion of complete fairness, if one had never experienced unfairness, while unfairness does seem to be something we can experience without first knowing its opposite. The lack is in some sense more real than the positive form.

So our supposedly positive notion is, in fact, being constructed defensively. We would like our most basic definitions to be the first moves in an argument, and not defensive ones. Otherwise, we are suspicious that there are more basic notions we have missed, and we should fall back on those instead.


The question, whether an absence can be a cause, is a profound one. However, I believe it is not really related to the epistemological question at hand. The paragraph that you quoted is confused about that.

The problem in using the term luck in a definition of knowledge is not related to being, to absence, or to causation. The real problem in clarifying knowledge by luck is that (1) the concept of luck is itself unclear; and in particular (2) it is doubtful whether the concept of luck could be clarified without invoking the concept of knowledge. So that if we attempt to clarify the concept of knowledge by the concept of luck, we will be moving in a vacuous circle.

Consider a person A looking at a clock that is showing the hour 8 am, and judging upon that the hour is 8 am. Suppose also (1) that the hour is indeed 8 am, but (2) that the clock is really defective, and (3) that a person B intentionally set the clock to 8 am, unknown to person A. Now A's judgement that the hour is 8 am is a justified true belief; yet it does not seem to be an instance of knowledge. But it is also does not seem to be a matter of luck. After all B intentionally rigged the clock, so it's not luck. Or is it?..


Your example is incorrect.

If you "lack knowledge of epistemology" you could hardly desire to learn it. You wouldn't know of its existence. Your desire to "learn epistemology" is caused by your "knowledge of epistemology" and and its apparently incomplete state.

The negative statement of a prior cause is always possible. We may say an infant is "caused" to cry by "lack" of food, or we may say the "cause" is the "presence" of certain neural discharges. It becomes a matter of what one accepts as the a priori cause. If you add up -1 + 1 + -1 + 1.... it depends entirely on how you bracket this "causal" series and which one you take as the beginning whether you get 1 or 0 as the "sum."

Having said this, I agree that the introduction of "nothing" into modern philosophy was a very important development, akin to the admission of zero into mathematics, and implies a certain potency, perhaps among the Aristotelean "final" causes. The beginning of Hegel's Logic develops all "becoming" out of the oscillation of "being" and "nothing," so that a relative "nothing" is indeed an essential part of any motion, change, causation.

We might say that "nothing" cannot be a "cause".... all by itself. But, of course, neither can "something" or "anything else."

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    I have to add here that the dialectics of positive and negative used by Hegel were prominent in Fichte's philosophy. Hegel "only" added the sublation.
    – Philip Klöcking
    Jan 4, 2016 at 1:57

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