Greek | ἐπιστήμη | the study of belief/knowledge

Epistemology is the study of the nature and scope of knowledge and justified belief. It analyses the nature of knowledge and how it relates to similar notions such as truth, belief and justification. It also deals with the means of production of knowledge, as well as scepticism about different knowledge claims. It is essentially about issues having to do with the creation and dissemination of knowledge in particular areas of inquiry.

Epistemology asks questions like: “What is knowledge?”, “How is knowledge acquired?”, “What do people know?”, “What are the necessary and sufficient conditions of knowledge?”, “What is its structure, and what are its limits?”, “What makes justified beliefs justified?”, “How we are to understand the concept of justification?”, “Is justification internal or external to one’s own mind?”

The kind of knowledge usually discussed in Epistemology is propositional knowledge, “knowledge-that” as opposed to “knowledge-how” (for example, the knowledge that “2 + 2 = 4”, as opposed to the knowledge of how to go about adding two numbers).

What Is Knowledge?

Knowledge is the awareness and understanding of particular aspects of reality. It is the clear, lucid information gained through the process of reason applied to reality. The traditional approach is that knowledge requires three necessary and sufficient conditions, so that knowledge can then be defined as “justified true belief”:

  • truth: since false propositions cannot be known – for something to count as knowledge, it must actually be true. As Aristotle famously (but rather confusingly) expressed it: “To say of something which is that it is not, or to say of something which is not that it is, is false. However, to say of something which is that it is, or of something which is not that it is not, is true.”
  • belief: because one cannot know something that one doesn’t even believe in, the statement “I know x, but I don’t believe that x is true” is contradictory.
  • justification: as opposed to believing in something purely as a matter of luck.

The most contentious part of all this is the definition of justification, and there are several schools of thought on the subject:

  • According to Evidentialism, what makes a belief justified in this sense is the possession of evidence – a belief is justified to the extent that it fits a person’s evidence.

  • Different varieties of Reliabilism suggest that either: 1) justification is not necessary for knowledge provided it is a reliably produced true belief; or 2) justification is required but any reliable cognitive process (e.g. vision) is sufficient justification.

  • Yet another school, Infallibilism, holds that a belief must not only be true and justified, but that the justification of the belief must necessitate its truth, so that the justification for the belief must be infallible.

Another debate focuses on whether justification is external or internal:

  • Externalism holds that factors deemed “external” (meaning outside of the psychological states of those who are gaining the knowledge) can be conditions of knowledge, so that if the relevant facts justifying a proposition are external then they are acceptable.

  • Internalism, on the other hand, claims that all knowledge-yielding conditions are within the psychological states of those who gain knowledge.

As recently as 1963, the American philosopher Edmund Gettier called this traditional theory of knowledge into question by claiming that there are certain circumstances in which one does not have knowledge, even when all of the above conditions are met (his Gettier-cases). For example: Suppose that the clock on campus (which keeps accurate time and is well maintained) stopped working at 11:56pm last night and has yet to be repaired. On my way to my noon class, exactly twelve hours later, I glance at the clock and form the belief that the time is 11:56. My belief is true, of course, since the time is indeed 11:56. And my belief is justified, as I have no reason to doubt that the clock is working, and I cannot be blamed for basing beliefs about the time on what the clock says. Nonetheless, it seems evident that I do not know that the time is 11:56. After all, if I had walked past the clock a bit earlier or a bit later, I would have ended up with a false belief rather than a true one.

How Is Knowledge Acquired?

Propositional knowledge can be of two types, depending on its source:

  • a priori (or non-empirical), where knowledge is possible independently of, or prior to, any experience, and requires only the use of reason (e.g. knowledge of logical truths and of abstract claims); or
  • a posteriori (or empirical), where knowledge is possible only subsequent, or posterior, to certain sensory experiences, in addition to the use of reason (e.g. knowledge of the colour or shape of a physical object, or knowledge of geographical locations).

Knowledge of empirical facts about the physical world will necessarily involve perception, in other words, the use of the senses. But all knowledge requires some amount of reasoning, the analysis of data and the drawing of inferences. Intuition is often believed to be a sort of direct access to knowledge of the a priori.

Memory allows us to know something that we knew in the past, even, perhaps, if we no longer remember the original justification. Knowledge can also be transmitted from one individual to another via testimony (that is, my justification for a particular belief could amount to the fact that some trusted source has told me that it is true).

There are a few main theories of knowledge acquisition:

  • Empiricism, which emphasizes the role of experience, especially experience based on perceptual observations by the five senses in the formation of ideas, while discounting the notion of innate ideas. Refinements of this basic principle led to Phenomenalism, Positivism, Scientism and Logical Positivism.

  • Rationalism, which holds that knowledge is not derived from experience, but rather is acquired by a priori processes or is innate (in the form of concepts) or intuitive.

  • Representationalism (or Indirect Realism or Epistemological Dualism), which holds that the world we see in conscious experience is not the real world itself, but merely a miniature virtual-reality replica of that world in an internal representation.

  • Constructivism (or Constructionism), which presupposes that all knowledge is “constructed”, in that it is contingent on convention, human perception and social experience.

What Can People Know?

The fact that any given justification of knowledge will itself depend on another belief for its justification appears to lead to an infinite regress.
Scepticism begins with the apparent impossibility of completing this infinite chain of reasoning, and argues that, ultimately, no beliefs are justified and therefore no one really knows anything.
Fallibilism also claims that absolute certainty about knowledge is impossible, or at least that all claims to knowledge could, in principle, be mistaken. Unlike Scepticism, however, Fallibilism does not imply the need to abandon our knowledge, just to recognize that, because empirical knowledge can be revised by further observation, any of the things we take as knowledge might possibly turn out to be false.
In response to this regress problem, various schools of thought have arisen:

  • Foundationalism claims that some beliefs that support other beliefs are foundational and do not themselves require justification by other beliefs (self-justifying or infallible beliefs or those based on perception or certain a priori considerations).

  • Instrumentalism is the methodological view that concepts and theories are merely useful instruments, and their worth is measured by how effective they are in explaining and predicting phenomena. Instrumentalism therefore denies that theories are truth evaluable. Pragmatism is a similar concept, which holds that something is true only insofar as it works and has practical consequences.

  • Infinitism typically takes the infinite series to be merely potential, and an individual need only have the ability to bring forth the relevant reasons when the need arises. Therefore, unlike most traditional theories of justification, Infinitism considers an infinite regress to be a valid justification.

  • Coherentism holds that an individual belief is justified circularly by the way it fits together (coheres) with the rest of the belief system of which it is a part, so that the regress does not proceed according to a pattern of linear justification.

  • Foundherentism is another position which is meant to be a unification of foundationalism and coherentism.


Mastin, L. (2009). Epistemology. Retrieved, philosophybasics.com/branch_epistemology
Penguin (2007). The Penguin English Dictionary (3rd ed.). London: Penguin

#00—Who am I?

pointless pleasurable ponderings

It is a valid question. But it is not one I, you or anyone else has yet to satisfactorily answer. I mean to say, if it was readily answerable, it wouldn’t be one that we see asked again and again and again. We aren’t just numbers—but as e.g., citizens, drivers, employees, students etc., &c. we are numerically referenced—we do have identities, but these identities are largely manufactured and, for the most part, made up in our heads. We are homo sapiens, we are fauna (i.e., not flora), we are a form of animal species and as animals we (but not all of us) are going to do, or have already done, certain things to replicate ourselves: to reproduce our (selfish)genes.

Here are some questions and topics that will first need to be considered before we can return to the vexed/complex and quite possibly pointless (but nevertheless, pleasurable to ponder) question of “Who am I?” You will notice the list is reflective of the zeitgeist of our times, trepidation with respect to man’s impact on the natural environment (because it is man isn’t it).

#01—Does life have meaning?
#02—What is truth?
#03—Is truth important?
#04—Superstition & scientific knowledge
#05—Is the mind an effect of the body?
#06—Theories on consciousness…
#07—If a tree falls in a forest…
#08—Rights for future generations?
#09—The deep ecology view…
#10—Climate change & moral responsibility

(I want to be free to speak my mind & I want to be free to wear what I like; this is what I am about and this is who I am.* *but I am not who I want to be and most likely I will never be.)

Obviously I am someone, but my identity itself, is of no consequence to answering this question; or to investigate the question as no clear answer will be provided (not least because until now, no convincing answer has been proffered).

#01—Does life have meaning?

pleasurably pondering pointlessly

To answer the question we need to consider what meaning means, does it mean purpose? Or, does it mean a deeper meaning? (whatever that itself is meant to mean! It is said that Plato once said (wo)man is “a being in search of meaning.”

Because in fact life has a very simple — prosaic — point and purpose and it is this:

As Burton (2018) confirms, historically and today also, many people believe that humankind is the creation of a supernatural entity… yet at Lawton (2016) points out, no one has proved that God exists, but then no one has proved there is no God. Is working out the truth a supernatural feat?

Human life may not have been created with any predetermined purpose, but this need not mean that it cannot have a purpose, nor that this purpose cannot be just as good as, if not much better than, any predetermined one.

And so the meaning of life, of our life, is that which we choose to give it.

As Hendricks (2018) argues, Dewey encourages us to stop looking at education as preparation for a job. Rather, it must be considered as a tool to help giving meaning to our lives. The contention was that this would not only improve a given country’s educational system (etc.) but would also allow its citizens to live more meaningful lives.

This is of course the foundational and seminal philosophical question, it is seemingly articulated somehow in the following works of art:

Clockwise, [1] The Venus of Urbino (1533) by the Italian painter Titian. [2] The Scream or The Scream of Nature (1893) by the Norwegian painter Edvard Munch. [3] Ascent of the Blessed (c.1510) and [4] The Garden of Earthly Delights (c.1500) by the Dutch painter Hieronymus Bosch. [5] Where Do We Come From? What Are We? Where Are We Going? (1897) by the French painter Paul Gauguin.


Burton, N. (2018). What is the Meaning of Life? Psychology Today.
Hendricks, S. (2018). 5 American philosophers on the meaning of life. Big Think.
Lawton, G. (2016). Metaphysics special: What is the meaning of life? New Scientist. Retrieved, https://www.newscientist.com/round-up/metaphysics/
Metz, T. (2013). The Meaning of Life. The Stanford Encyclopedia of Philosophy. Retrieved, https://plato.stanford.edu/entries/life-meaning/
Steed, E. (2018). Philosophy Illustrated. The New Yorker.
Wikipedia (2019). Meaning of Life. Wikipedia. Retrieved, https://en.wikipedia.org/wiki/Meaning_of_life

#07—If a tree falls in a forest…

pleasurably pondering pointlessly

This is a classic thing to consider (a question that may better be considered as a sort of infallible conjecture):

If a tree falls and no living thing with the ability to hear it fall hears it, did it actually make a sound?

Well, I’ll say yes! [yes it does make a sound] But it was a sound that no member of the fauna class heard. It is important to remember that sound is noise traveling along airwaves. The energy released from the falling of a tree would thus have created a sound (albeit a sound that no known listening device was around to hear).

As Wikipedia (2019) reveals, the magazine Scientific American corroborated the technical aspect of this question, while leaving out the philosophic side, “sound is vibration, transmitted to our senses through the mechanism of the ear, and recognised as sound only at our nerve centers. The falling of the tree or any other disturbance will produce vibration of the air.”

We could say then that “sound” is something within human experience. Outside of this it’s just vibrations in the air. Indeed, many argue (see, e.g., The Guardian, n.d.) that the definition of a sound is its detection, rather than the physical phenomenon.

Consider this, once we develop an instrument that can detect vibrations we couldn’t otherwise hear, a previously ‘non-existent’ sound comes into being.

So, if someone is there to hear the rapid movement of particles we can say it makes a sound, if no human is there to hear it fall, the fall will still cause the rapid movement of particles [i.e., what humans term: “sound”] but it will be one that falls on deaf ears (however! the hedgehog and the fox may/may not have been there to hear).*]

Scientifically-speaking, sound is sound and it is not contingent on humankind being around to interpret it. We are oh so anthropocentric aren’t we!

This question of the falling tree is really considering another question, do things that happen outside of our senses actually happen…

Full many a flower is born to blush unseen, And waste its sweetness on the desert air.

— Thomas Gray (English poet, 1716-1771)

In a poetic way, Gray is saying how many beautiful flowers bloomed without every being seen by a human’s eyes. We can’t know for sure that these beautiful flowers lived and died (because we or nobody else saw their rise and fall) but our instinct and knowledge of flora would lead us to assume that yes such beautiful blossomings happen irrespective of if we are there to see them or not.

The truth of the matter is this, thequestion of the tree falling out of earshot is really designed to hint to a more profound ethical question: if we are unaware of somebody’s suffering, does their suffering exist? (for us no, for them [and other’s who’ve guessed/been told] yes). It relates to the ideas of immaterialism proposed by George Berkeley some 300 years ago, who argued that the only things that exist are ideas and the human mind that is having/holding those ideas (BBC, 2015).

Subjective idealism | metaphysics | ‘only minds and mental contents exist’

Berkeley, in his book, A Treatise Concerning the Principles of Human Knowledge (1710), argues that, “But, say you, surely there is nothing easier than for me to imagine trees, for instance, in a park […] and nobody by to perceive them.[1] […] The objects of sense exist only when they are perceived; the trees therefore are in the garden […] no longer than while there is somebody by to perceive them.”


Metaphysics is the branch of philosophy that examines the fundamental nature of reality, including the relationship between mind and matter, between substance and attribute, and between possibility and actuality.

Metaphysics studies questions related to what it is for something to exist and what types of existence there are. Metaphysics seeks to answer, in an abstract and fully general manner, these two questions:

  • What is there?
  • What is it like?

From terrestrial to lunar

Albert Einstein is reported to have asked a fellow physicist Niels Bohr whether he realistically believed that ‘the moon does not exist if nobody is looking at it.’ To this Bohr replied that however hard one may try, they would not be able to prove that it does. This is, according to Mendis (2009) a fine example of an infallible conjecture (i.e., it cannot be either proved or disproved; sound familiar? “Timber!” cried the mute lumberjack).

* “The fox knows many things, but the hedgehog knows one big thing.” This ancient Greek aphorism, preserved in a fragment from the poet Archilochus, describes a thesis put forward by Isaiah Berlin regarding the philosophy of history. Although there have been many interpretations of the aphorism, Berlin uses it to mark a fundamental distinction between human beings who are fascinated by the infinite variety of things and those who relate everything to a central, all-embracing system.

Berlin’s extraordinary essay offers profound insights about Tolstoy, historical understanding, and human psychology (Kobo, 2019). According to Berlin, humans can be divided into two categories: hedgehogs, who view the world through the lens of a single defining idea (he cites: Plato, Dante Alighieri, Hegel, Nietzsche and Proust), and foxes, who draw on a wide variety of experiences and for whom the world cannot be summed up into a single idea (he cites: Aristotle, Desiderius Erasmus, William Shakespeare, and James Joyce) (Wikipedia, 2019b).


BBC (2015). A history of Ideas. British Broadcasting Corporation. Retrieved, bbc.co.uk/programmes/p02yq1b9
Kobo (2019). The Hedgehog and the Fox. Kobo
Mendis, M. (2009). Of Trees Falling in the Forest, on the anthropocentrism of philosophy. Big Think. Retrieved, bigthink.com/of-trees-falling
Steed, E. (2018, 25 June). Philosophy Illustrated. The New Yorker.
The Guardian (n.d.) Ethical Conundrums. The Guardian.
Wikipedia (2019a). If a tree falls in a forest. Wikipedia. Retrieved, wikipedia.org/wiki/
Wikipedia (2019b). The Hedgehog and the Fox. Wikipedia. Retrieved, wikipedia.org/wiki/


#06—Theories on consciousness…

pleasurably pondering pointlessly

What is consciousness… Why’s the sky blue? (Chemistry and physics will know) How long’s a piece of string? (Engineers and mathematicians will know). But as to the question what is consciousness? Nobody really knows. Biologists can dissect us, cognitive scientists and psychologists can analyse us, but only really philosophers spend their lives pondering what exactly consciousness is.


Steed, E. (2018, 25 June). Philosophy Illustrated. The New Yorker.