An Introduction to Analytic and Synthetic Judgments in Kant
The topic at hand is the importance for Kant of distinguishing synthetic a priori judgments from analytic a priori judgments and synthetic a posteriori judgments. Reference will be made to the Critique of Pure Reason (CPR) and the Prolegomena to Any Future Metaphysics (PFM).
Because Kant’s terms are often compound and loaded heavily with idiosyncratic and complex meaning, my account of this topic will for the most part first focus on an explication of a few salient terms and distinctions between concepts. It will then turn to examining some reasons why these notions are important for his overall project of rescuing the tentative science of metaphysics. The aim is of course not a full, thorough, systematic account of the way these concepts are utilized and deployed for Kant, but merely a presentation of them as non-trivial, functional, ground-level concepts in his Critique and metaphysical scheme.
What the notion of “judgment” is for Kant, independent of the delineators “analytic” or “synthetic,” is not immediately clear, although it is a term he uses abundantly and defines several times in CPR (B94 and B141, for example). A mean definition based on those given in CPR might refer to judgment as the “function of unity among representations,” an act of the understanding that brings intuitions under concepts (CPR B94-95). To further elucidate, an intuition is an immediate presentation of a specific object and a concept refers to an object or class of objects indirectly via some characteristic (CPR B376-377). Concepts can be empirical abstractions or they can be pure, in the sense of existing without being abstracted from empirical data.
For Kant, a distinguishing feature of reason’s a priori cognitions (defined as conscious mental representations – CPR B376) is that they can have the force of objective necessity and of universality, neither of which experience-based a posteriori cognitions can have except in a limited inductive way (CPR B3-4). Kant also distinguishes between a priori judgments and absolutely a priori judgments; absolutely a priori judgments are judgments which are derived from other a priori propositions that are valid and necessary (CPR B4).
Kant perspicuously explains in PFM §2 the distinction between analytic and synthetic judgments. The content of an analytic judgment must be “merely explicative,” expressing explicitly only what is implicitly in the concept of its object. It is analytically true that a square has four sides because having four sides is contained in the concept of a square. But Kant would say that this kind of analytic a priori judgment does not (and cannot) have ampliative content. In order to have ampliative content, or content that expands our concepts, the judgment must be synthetic. Synthetic judgments are judgments in which the nature of the concept(s) does not circumscribe our ability to derive content from them. For example, nothing in the nature of a “straight line” or of “points” considered only in terms of themselves seems to imply that a straight line is the shortest distance between any two points. Yet we can make the synthetic judgment that this relation between the concepts is true. Further, nothing in the concept of 4, 6, or their product shows us that, multiplied, they give us 24, but we can make the synthetic judgment that this relation holds. From these and other mathematical judgments we can derive more concepts and more judgments, fully a priori. These examples are meant to show how a priori judgments can be synthetic as well as analytic. For Kant, it is absolutely critical to demonstrate successfully that mathematical judgments fall under the category of synthetic, not analytic, a priori judgments, for reasons to be explained shortly.
As to the import of these distinctions and terms and the topic presented at the beginning of the paper, Kant provides a starting-point in his own words:
“Now the real problem of pure reason is contained in the question: How are synthetic judgments a priori possible? That metaphysics has hitherto remained in so vacillating a state of uncertainty and contradiction is entirely due to the fact that people have never previously thought of this problem, or perhaps even of a distinction between analytic and synthetic judgments. The solution of this problem…is a question of life or death to metaphysics.” (CPR B20)
So clearly Kant considered the analytic/synthetic distinction, especially among a priori judgments and concepts, to be of critical import to his entire project. To show why and how these concepts are deployed, it is proper to present them in their context.
Kant desired to “save” non-empirical metaphysics from empiricist (Humean) objections because he believed that the objects of metaphysical investigation, namely God, freedom, and immortality, were “excellent” and because he took the “final aim” of these investigations to be “far more sublime” than anything our understanding can learn “in the realm of appearances” (CPR B7). Humans have a natural inclination for the investigation of nonempirical metaphysics and the study of metaphysical concepts enriches our lives, frames our ontology, provides reason for us to be moral, and girds us against the deep perturbations of an all-pervasive skepticism that is the reverse side of a strictly inductive empirical pseudo-metaphysics.
Kant wanted to bring an argument forth that might show how pure a priori concepts can be derived and constructed, since these would constitute any meaningful metaphysics as both a natural disposition and potential science (CPR B20-23). However, Kant realized he could not do this in traditional dogmatic (mathematical, scientific) fashion without critique of the capacities of “the organ” of metaphysics – this being pure reason, the domain of the absolutely a priori (CPR Bxxxv). One reason Kant had to discard uncritical dogmatic metaphysics is because, through Hume, he had come to recognize the limits of mere analytic judgments as explained above, with the concept of cause and effect serving as the example of faulty and falsely named a priori reasoning which was actually synthetic and an a posteriori induction derived from repeated experience (PFM 257). However, the notion of synthetic a priori judgments and concepts provided an avenue for Kant to address the radical conclusions proposed by Hume. Hume believed a pure mathematical science was possible, so by demonstrating that mathematical judgments are synthetic a priori judgments, Kant believed he had found a refutation to Hume’s broad skepticism of the possibility of synthetic a priori knowledge and an inroad to demonstrating the possible validity of a new science of metaphysics in spite of its longstanding tradition of inefficacy (CPR B20).
To effectively lay the groundwork for a valid and scientific metaphysical paradigm, Kant would necessarily need to begin by circumscribing the domain of pure reason. He would do so by defining his terms in unprecedented (or at least not in any sense widely adopted) ways, showing how some a priori judgments may differ from others and how a priori judgments categorically differ from a posteriori judgments but can have parallel methods of construction. Upon this foundation alone could he build a “post-critically dogmatic” metaphysics, where we take dogmatic to mean “scientifically and systematically proceeding from absolute principles” and “post-critically” to mean “proceeding with a proper sense of the scope and domain of pure reason.”