© Michael Lacewing

Hume and Kant

Michael Lacewingenquiries@alevelphilosop

hy.co.uk

Analytic and synthetic propositions

• An analytic proposition is true or false in virtue of the meanings of the words.

• A synthetic proposition is one that is not analytic, i.e. it is true not in virtue of the meanings of the words, but in virtue of the way the world is.

A priori knowledge

• A priori: knowledge that does not require (sense) experience to be known to be true (v. a posteriori)

• It is not a claim that no experience was necessary to arrive at the claim, but that none is needed to prove it.

Rationalism v. empiricism

• Rationalism: we can have substantive a priori knowledge of how things stand outside the mind.– Substantive knowledge is knowledge

of a synthetic proposition. Trivial knowledge is knowledge of an analytic proposition.

• Empiricism: we cannot.

Hume’s fork

• We can only have knowledge of – Relations of ideas– Matters of fact

• Relations of ideas are a priori and analytic

• Matters of fact are a posteriori and synthetic

Knowledge of matters of fact

• We gain it by using observation and employing induction and reasoning about probability.

• The foundation of this knowledge is what we experience here and now, or can remember.

Kant on ‘experience’

• What would it be like to have sensory experience but with no ability to think about it?

• It would not be experience of anything - the idea of an object is the idea of something that is unified, existing in space and time

• What makes intelligible experience, of objects, possible?

Categories

• Kant’s answer: certain basic concepts, under which sensory input falls, provide experience; Kant calls these concepts ‘categories’

• This conceptual scheme is necessary for any intelligible experience at all, i.e. necessary for experience of objects

• How does Kant show this?

Causality

• To experience a (physical) world of objects, we must be able to distinguish the temporal order of our experiences from the temporal order of events.

• Compare two easily made judgments:– Look around the room - your perceptual

experience changes, but the room itself has not changed

– Imagine watching a ship sail downstream - your perceptual experience changes, and you say that the scene itself has changed (the ship has moved)

Causality

• How can we make this judgment?• The room: we could have had the

perceptions in a different order, without the room being different

• The ship: we could not have had the perceptions in a different order, unless the ship was moving in a different way

• With the ship, the order of perceptual experience is fixed by the order of events; the order must occur as it does.

Causality

• This is the idea of a ‘necessary temporal order’, which is captured by the concept CAUSALITY.

• Effects must follow causes - where one event does not repeatedly follow another, there is no causal link between the events.

• CAUSALITY is the concept that events happen in a necessary order.

Causality

• Without this concept, I cannot distinguish between the order of my perceptions (my perceptions changing) and the order of events (objects changing).

• But this distinction is needed to experience objects at all. So CAUSALITY is necessary for experience.

Conceptual scheme

• Kant provides other argues for necessity, unity, substance…

• They are each aspects of ‘the pure thought of an object’

• They are not derived from experience, but logically precede experience - hence they are a priori and innate, part of the structure of the mind.

Conceptual scheme

• We do not apply these concepts to experience - there is no experience without these concepts. At best, there is a ‘confused buzz’ - but do you experience a confused buzz?? Does it even truly occur, at some moment before applying the concepts?

• All conceptual schemes must include the categories - this is not given by empirical argument, but a priori argument. There is therefore a limit on conceptual relativism.

Mind and world

• What is the world like independent of these concepts? We cannot say, we cannot even imagine. All thought about the world presupposes these concepts.

• This casts no doubt on the physical world as we experience it - this we can know contains physical objects etc. - anything that takes the form of an ‘object’ is something to which our concepts have already been applied.

• There is nothing we could know here, but don’t. What would it be to know anything without using concepts? What is experience that is not experience of objects?