Class and book notes on Kant

(Originally written September 10, 2006 in Book 8)

A priori knowledge

Classifications and Definitions

"The problem of synthetic a priori knowledge involves epistemological, metaphysical and semantic considerations" (Pojman, 367).

"A priori and a posteriori are latin terms that were first developed in the Middle Ages by scholastic philosophers.

Leibniz used both to prove knowledge. Kant further developed the notions.

Is there synthetic a priori knowledge? Kant held that it was necessary from a logic standpoint.

"A. Epistemological Categories

1. A priori knowledge does not depend on evidence from sense experience. (Plato's innate ideas and Leibniz's 'truths of reason') for example, mathematics and logic.

2. A posteriori knowledge depends on evidence from Sense experience. (Plato's 'appearance' and Leibniz's 'truths of fact') - empirical knowledge.

B. Metaphysical Categories

1. Necessary truths 'are' true in all possible worlds (for example, the statement that, 'God exists' according to the ontological argument).

2. Contingent truths 'are' true in the actual world but not in all possible worlds (for example, the fact you exist and were born after January 1, 1800)

C. Semantical categories

1. Analytic-predicate is contained in the subject, explicative, not ampliative (for example, 'all mothers are women')

2. Synthetic - predicate is not contained in the subject but adds something to the subject ampliative, not explicative (for example, Mary is a mother)" (Pojman, 367-8)

Combinations

Synthetic a priori knowledge is affirmed by rationalists and denied by empiricists.

Neither believe that there are such things as analytic a posteriori knowledge because that implies a contradiction.

Kant, a radical rationalist, held that all knowledge was grounded in a priori knowledge.

"The essential claim of those who hold to synthetic a priori knowledge is that the mind can grasp connexions between ideas (concepts) that are not strictly analytical related" (Pojman, 368).

Kant's Chart of Knowledge

	Analytic	Synthetic
A Priori	-Entailments -Identity Statements -Tautologies -Definitions	-Mathematics -Exclusionary -Presuppositions of experience -Moral Judgments -Laws of Logic -Metaphysical
A Posteriori	XX	-Empirical “All bodies are heavy” “John is a bachelor”

(clarifications are for my own sake)

Synthetic a priori knowledge

-Math, i.e. 5+7=12

-Exclusionary: i.e. nothing red is green

-Presuppositions of experience: space, time and causality

-Moral judgments - the categorical imperative

-The Laws of Logic: i.e. The principle of non-contradiction

-Metaphysical - The existence of God, Free-Will

The Kantian Theory About Synthetic A Priori Knowledge

The question: How are synthetic a priori judgments possible? This is Kant's primary concern in his Critique of Pure Reason.

Kant (via Ewing) makes four claims about synthetic a priori judgments

1. They are logically necessary - wholes that determine their own parts

2. They are not derivable from particular sensations (but empirical experience is the trigger to cause them to arise)

3. They are presupposed in all of our experience

4. They are contributed by our minds.

Synthetic a priori knowledge is of the conditions of experience, not of reality.

A.J. Ayer critiques the notion of the synthetic a priori knowledge from a conventionalist's point of view. He believes that all the supposed a priori knowledge can actually be reduced to analytic truths.

A.C. Ewing counters Ayer and is in favor of it. Maintaining that if nothing else, the laws of logic are a priori.

W.V. Quine denies the notion of containment being meaningful. (Containment is the notion of an idea being expressed in the definition of the word: bachelor contains the ideas 'unmarried' and 'man'). Since Quine denies containment then he makes no distinction betwixt analytic and synthetic judgments. This also rids him of a priori judgments.

H.P. Grace and P.F. Stranson disagree with Quine.

Roderick Chisholm defends a priori and analytic knowledge. 

Saul Kripke throws a major curveball, contending that is possible to have a posteriori necessary truths and non-necessary a priori knowledge.

VII.1. A Priori Knowledge 

Immanuel Kant

Kant (1724-1804) was born in Königsberg and never left the town.

He was deeply pious and Lutheran

He was inhuman in his orderliness. Some citizens of Königsberg set their clocks by Kant's walks.

The Critique of Pure Reason started a revolution in theory of knowledge.

He was "woke from his dogmatic slumber" by Hume. 

Kant held that we have incredible structured minds that interpret and categorize all experiences that we have. This is the "Kant's Copernican Revolution"

Kant's distinctions between a priori and a posteriori knowledge is famous.

A priori knowledge is what we know prior to experience. A posteriori is knowledge we gain through experience.

Hume considered all knowledge of matters of fact a posteriori and only analytic statements a priori.

Kant rejects Hume's theory and states that it is possible to have a priori knowledge of matters of fact.

Kant holds that all knowledge begins with experience, but it does not mean that all knowledge arises out of experience.  

Kant also holds that mathematical truth is synthetic (the predicate ads something to the subject) not analytical.

Other synthetic a priori knowledge is knowledge of time, of space and of causality.

	A priori	A Posteriori
Analytic	Tautologies & entailments	None
Synthetic	Causality, Space and time, 5+7=12, and the moral law	Empirical judgments

Until Kant, people believed our knowledge must conform to objects. This had led to a failure to establish a priori knowledge. Kant switched it around so that objects conform to out knowledge, making a priori knowledge possible. This is Kant's so-called Copernican revolution.

Prolegomena: Preamble on the Peculiarities of all Metaphysical Knowledge

S1. Of the Sources of Metaphysics

Sciences differ from one another based on one or all of these:

1) object

2) sources of knowledge

3) kind of knowledge

As for metaphysics and its knowledge, it can never be, or come from things, empirical.

It can not be from external experiences because that is physics; nor can it e from internal experiences because that is psychology. Therefore, ti must come from a priori knowledge. It comes from pure understanding and pure reason.

Metaphysics is pure philosophical knowledge.

S2. Concerning the kind of knowledge which can alone be called metaphysical

Metaphysical judgments are judgments that are explicative, that is, they add nothing to their content.

Synthetical judgments are judgments that are expansive, that is, they increase the knowledge.

Analytical judgments merely analyze the subject in the predicate: 'All bodies are extended'.

Synthetical judgments add something to the subject in the predicate: 'All bodies have weight' 

The common principle in all analytical judgments is the law of contradiction.

Basically, an analytic judgment explicitly states a subject and its definition in the predicate. If an analytic statement contradicts itself it is false.

There are two types of synthetical judgments:

1) a priori

2) a posteriori

Synthetical judgments cannot be deduced solely from the Law of Contradiction, but they are still subject to it.

Judgments of experience are always synthetical by nature.

Mathematical judgments are synthetical. This is a fact that eluded people for years.

All mathematical judgments are a priori because they are necessarily true.

Arithmetic judgments like 5+7=12 are definitely true because there is nothing in the notions '5', +, '7' that demands the sum of 12.

Linehan - I think I disagree. The concept of '12', if we truly know it can be analyzed and known as, '0+12, 1+11, 2+10, 3+9, 4+8, 5+7, 6+6, and so forth, provided that we know the notion of '7".

Geometrical judgments are likewise synthetical because they require us to use intuition tadas.

"the essential and distinguishing feature of pure mathematical knolsedge among all after a priori knowledge is that it cannot proceed from concepts, but only from construction of concepts" (Pojman, 373).

Kant criticizes Hume for believing mathematics contained only analytical propositions and metaphysics having only synthetical a priori propositions. But, had Hume realized that mathematics were a priori synthetical propositions he would not have discarded metaphysics.

Metaphysical judgments are synthetical. But, judgments pertaining to metaphysics are analytical.

Definitions like a substance is that which exists as a subject is an analytical judgment pertaining to metaphysics. The concept "substance" is metaphysical but the judgment is analytical and therefore, not a metaphysical judgment.

Metaphysics is different from every other science in the way it produces its a priori cognitions.

Metaphysics receives from outside itself analytic judgments, but uses those analytic judgments to accomplish its end, which is to form a priori synthetical judgments.

"The generation of a priori knowledge by intuition as well as concepts, in fine, of synthetical propositions a priori, especially in philosophical knowledge, constitutes the essential subject of metaphysics" (Pojman, 374).

S3. A remark on the general division of judgment into analytical and synthetical:

The distinction is extremely important, but it is difficult to find in other men's work. It is obscure, and difficult to put into words. Once one discovers it though, they will be able to see the difference in places where they never saw it before.

S4. The General Question of the Prolegomena: Is Metaphysics Possible?

We cannot assume that metaphysics exists as a science, but we can confidently state that there are a priori synthetical cognitions (i.e. pure mathematics).

The question is not whether, but how is metaphysics possible?

S5. The General Problem: How is knowledge from pure reason possible?

Metaphysics stands or falls on the ability or inability to have synthetic a priori knowledge.

There can be an incredibly well put together metaphysical system with tons of truths, but if the architect of that system has not given an account to how one comes to know a priori synthetic judgments then, "to all that which thou protest me thus, I refuse to give credence, and hate"

If we did not see true synthetical a priori judgments in life then we would see that the question of how to come by that knowledge as insoluble.

To solve this we must divide it into four parts:
1) How is pure mathematics possible?
2) How is pure natural science possible?
3) How is metaphysics in general possible?
4) How is metaphysics as a science possible?

I am so irritated! Kant spends this entire last section suspending others from metaphysics but gives no definite answer. Ahh! I am thoroughly agitated right now. This is on e of the biggest disappointments in my brief (about fourteen months now) investigation into philosophy!