Mary Kathryn Huffman (Married: Gough) / Kant Journal One / 2/17/04 Hardy
A Priori Synthetic Judgments
Kant wanted to make clear some defining lines in the muddiness of metaphysics, as it seemed to be making no progress beyond producing dogmatic bickering. At the very outset of the Critique of Pure Reason, he draws a key distinction between two kinds of knowledge (a priori and a posteriori). He then distinguishes between two kinds of judgments, one of which he calls ‘analytic’, the other ‘synthetic’. After describing the way that these two kinds of judgments have always been related to a priori and a posteriori knowledge, he reveals his intent to rearrange the strict definitions and bring to light a new pairing on the terms. The result, Kant says, is a hereto for unseen kind of judgment which constitutes metaphysics proper and ought to be recognized and examined: ‘a priori synthetic judgment’. This examination should, by definition, clarify for us what metaphysics really is, and allow us to state the problem of whether it is in fact possible in a more helpful way than ever before. Here I will attempt to lay out these definitions and connections in a clear and concise way in order to show how Kant found them relevant to the viability of the practice of metaphysics in philosophy.
Kant begins his momentous response to the stagnancy he finds in the discipline by making two important distinctions: one between a priori and a posteriori knowledge, and one between analytic and synthetic judgments. A priori knowledge is knowledge it is useless to doubt, knowledge which has the characteristic of being both necessary and universal. It is knowledge given prior to experience, based on something deeper in our being which is able to perceive more “than mere
experience would teach… certain cognitions [that] even abandon the field of all possible experiences and seem to expand the domain of our judgment beyond all bounds of experience through concepts to which no corresponding object at all can be given in experience” (p.128).
A posteriori knowledge, on the other hand, is based upon experience, giving itself in the empirical evidence to be found there.
A posteriori knowledge has always been linked with synthetic judgments in the past, according to Kant, because synthetic judgments add to or “amplify” our given concept of a thing, thus making use of experience in positing its new judgment (p.130). The statement that “all bodies are heavy,” is a synthetic judgment because our concept of a body does not in essence include heaviness as a necessary or universal characteristic. One must “first cognize the concept of a body
analytically through the marks of extension… etc. which are all thought in this concept…[and then] amplify [one’s] cognition and, in looking back to the experience from which [one] had extracted this concept of a body, [one] find[s] that weight is also always connected with the previous marks” (p.131).
But Kant shows that a priori knowledge has always been linked to analytic judgments, which he describes as being “clarifying” judgments that “break down concepts into their component parts” (p.130). The statement that “all bodies are extended” is an analytic judgment. This is because we need only analyze our concept of a body and “become conscious of the manifold that [we] always think in it… in order to encounter this predicate [extension] therein” (p.130). The predicate (extension) is found within the identity of the concept itself in an analytic judgment.
This brings out a question. The question, really. Where does metaphysics fit in this, and what type of knowledge and judgment are appropriate to it? It would seem that all the options are already taken, but Kant goes on from here to introduce and explain a kind of a priori synthetic judgment and to explain how understanding this overlooked kind of judgment will allow the possibility of the project of metaphysics to be stated and then analyzed properly. With four terms of two different kinds, there are four possible ways to link them up. Theoretically one could have a priori analytic judgments, a posteriori analytic judgments, a priori synthetic judgments, and a posteriori synthetic judgments. By definition, analytic judgments are a priori, and therefore cannot be a posteriori (Hoffe,p.41 and Kant,p.142). Synthetic judgments often take from experience to perform their ‘amplifying’ function and therefore the idea of a posteriori synthetic judgments is only natural. However a priori synthetic judgments are not by definition impossible (Hoffe,p.41). This possible pairing has been overlooked according to Kant, and we ought to consider it carefully, as it is not immediately obvious whether or not it is valid. Kant claims that the project of metaphysics, never having properly analyzed itself, did not know that it was constituted entirely by a priori synthetic propositions. This means that the question of “whether or not the conceptual possibility can also be realized and there actually are synthetic judgments a priori, that is, an expansion of knowledge prior to experience – this question decides the possibility of metaphysics as a science”(Hoffe, p41).
In a posteriori synthetic judgments, one can go back to experience in order to amplify one’s cognition and make a judgment, reflecting upon the evidence given to add to a preexisting concept. But in this new category of a priori synthetic judgments, Kant says, “this means of help is entirely lacking. If I am to go
outside concept A in order to cognize another B as combined with it, what is it on which I depend and through which the synthesis becomes possible, since I do not have the a advantage of looking around for it in the field of experience?” (p. 131).
This sort of activity is one in which the sciences have always engaged unawares. Mathematics makes use of it in the simple act of addition, finding that it has a pure intuition of the necessity of a sum and then positing a name from outside the identity of the pair of numbers for the result. “That 7 should be added to 5 I have,
to be sure, thought in the concept of a sum = 7+5,” says Kant, “but not that this sum is equal to the number 12. The arithmetical proposition is therefore always synthetic…” (p.144).
Physics “contains within itself synthetic a priori judgments as principles” as well, going beyond the known and experienced concepts of the natural world “in order to add something to it a priori that [we] did not think in it” (p.145). Each of these sciences bring a creative element into the knowledge process, and only by doing so are they able to make any progress at all. This idea is a result of Kant’s so called Copernican turn. As Höffe says, “about an object one can know with certainty only what one himself sets into its concept; only by creative thought and construction does scientific knowledge become accessible” (p.36).
In the project of metaphysics, precisely what we want to do is “to amplify our cognition a priori,” as Kant says, and “to this end we must make use
of such principles that add something to the given concepts that was not contained in them, and through synthetic a priori judgments go so far beyond that experience itself cannot follow us that far, e.g. In the proposition “The world must have a first beginning,” and others besides, and thus metaphysics, at least as far as its end is concerned, consists of purely synthetic a priori propositions” (p.146).
So metaphysics, being purely constituted by an “extending of its a priori cognition synthetically,” (Kant, p.148) is entirely founded upon the possibility of this a priori knowledge being valid, and on its being able to form a base for forming synthetic a priori propositions. Recognizing and understanding this new term, therefore, is key in beginning the trial before us. It defines exactly the conditions under which metaphysics will be pronounced a valid science, or, if she fails to meet these conditions, a useless waste of time.
c. Mary Kathryn Gough