The Brain in a vat

(are you an envatted brain?)
scepticism: how do we know what we know?

the philosophical skeptic doesn't claim that we know nothing--not least because to do so would be obviously self-defeating (one thing we could not know is that we know nothing). Rather the skeptic's position is to challenge our right to make claims to knowledge. We think we know lots of things, but how can we defend those claims? What grounds can we produce to justify any particular claim of knowledge? Our supposed knowledge of the world is based on perceptions gained via our senses, usually mediated by our use of reason. But are not such perceptions always open to error? Can we ever be sure we're not hallucinating or dreaing, or that our memory isn't playing tricks? [Epistemology]

Plato's cave

(earthly knowledge's but a shadow)

the cave represents 'the realm of becoming'--the visible world of our everyday experience, where everything is imperfect and constantly changing. The chained captives (us) live in a world of conjecture and illusion, while the former prisoner, free to roam within the cave, attains the most accurate view of reality possible, within the ever-changing world of perception and experience. By contrast, the world outside the cave represents the 'realm of being'--the intelligible world of truth populated by the objects of knowledge, which are perfect, eternal and unchanging.

what is known must not only be true but also perfect and unchanging. Nothing in the empirical world (represented by life within the cave) fits this description: a tall person is short next to a tree; an apple that appears red at noon looks black at dusk; and so on. As nothing in the empirical world is an object of knowledge, Plato proposed that there must be another ream (the world outside the cave) of perfect and unchanging ideas which he called 'Forms' or Ideas.

the problem of universals: realists/Platonists believe that universals such as redness and tallness exist independently of particular red and tall things; and the anti-realists/nominalists hold that they are mere names or labels that are attached to objects to highlight particular similarities between them. Modern debate continues: realists hold that there are entities 'out there' in the world--physical things or ethical facts or mathematical properties--that exist independently of our knowing/experiencing them. Anti-realists there must be a necessary and internal link or relation between what is known and our knowledge of it.

The veil of perception

(what lies beyond the veil?)

most of us uncritically suppose that physical objects around us are more or less what we perceive them to be, but some question that--in their view we have direct access to inner 'ideas', 'impressions' or 'sense data'; human understanding is like a closet wholly shut from light, with only some little openings left, to let in external visible resemblances, or ideas of things without. Our ideas, which are all that we have direct access to, form an impenetrable 'veil of perception' between us and the outside world. 'Representational' models of perception: any such model that involves intermediate ideas or sense data drives a wedge between us and the external world, and it is in the fissure so formed that skepticism about our claims to knowledge really exist. It is only by re-establishing a direct link between observer and external object that the veil can be torn and the skeptic vanquished. So, given that the model causes such problems, why adopt it in the first place? Locke hoped that by distinguishing between 'primary' and 'secondary' characteristics (one being intrinsic, the other perceptionally-influenced) he could disarm the skeptic.

Berkeley refuted it by saying that Locke could never actually check whether his supposed resemblances actually resembled the external things themselves, then took it to its conclusion and said that reality consists in the 'ideas' or sensations themselves; with these, we are already fully and properly connected, so the dangers of skepticism are evaded, but only at the price of the denial of an external, physical world. Berkeley's idealist (or immaterialist) theory states "to exist is to be perceived", and since God perceives all things, it remains in existence even when passing out of human perception.

cogito ergo sum

(I am thinking therefore I exist)

Reason & experience

(How do we know?)

The tripartite theory of knowledge

(When do we really know?)

The mind-body problem

(Mind boggles)

What is it like to be a bat?

(Inside a bat's mind?)

The Turing test

("Did you ever take that test yourself?")

The ship of Theseus

(What makes you, you?)

Other minds

(Is there anybody there?)

Hume's guillotine

(The is-ought gap)

One man's meat

(Is it all relative?)

The divine command theory

(Because God says so)

The boo/hooray theory

(Expressing moral judgements)

Ends & means

(The least bad option)

The experience machine

(Is happiness enough?)

The categorical imperative

(Duty at any cost)

The Golden Rule

(Do as you would be done by)

Acts & omissions

(To do or not to do?)

Slippery slopes

(If you give an inch...)

Beyond the call of duty

(Should we all be heroes?)

Is it bad to be unlucky?

(Does Fortune favor the good?)

Virtue ethics

(Who you are, not what you do)

Do animals feel pain?

(Animal cruelty)

Do animals have rights?

(Human wrongs?)

Forms of argument

(Infallible reasoning?)

The barber paradox

(If it is, it isn't)

The gambler's fallacy

(Against the odds)

The Sorites Paradox

(How many grains make a heap?)

The King of France is bald

(Language and logic)

The beetle in the box

(Language games)

Science & pseudoscience

(Evidence falsifying hypothesis)

Paradigm shifts

(science--evolution and revolution)

Occam's Razor

(Keep it simple)

What is art?

(Aesthetic values)

The intentional fallacy

(Meanings in art)

The argument from design

(The divine watchmaker)

The cosmological argument

(The first and uncaused cause)

The ontological argument

(The greatest imaginable being)

The problem of evil

(Why does God let bad things happen?)

The freewill defense

(Freedom to do wrong)

Faith & reason

(The leap of faith)

Positive & negative freedom

(Divided loyalties)

The difference principle

(Justice as fairness)


(The social contract)

The prisoner's dilemma

(Playing the game)

Theories of punishment

(Does the punishment fit the crime?)

Lifeboat Earth

(Is there more room in the boat?)

Just war

(Fight the good fight)

Tags: reading   books   philosophy   thinking  

Last modified 19 September 2022