© Michael Lacewing Hume and Kant Michael Lacewing 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?