Fichte uses the term systematic form a number of times in his essay Concerning the Concept of the Wissenschaftslehre. It is almost certain that Fichte’s concept of systematic form is rooted in Reinhold's writings, since it was Reinhold who impressed upon the age the idea that all philosophy must be systematic. I think Fichte's comments on systematic form are important because they help us understand how he conceived the logic of transcendental arguments to run. With that in mind, I want to share a few reflections on systematic form.
It seems to me that Fichte uses systematic form in two ways, one that is descriptive and one that is logical (normative). Systematic form is a descriptive property that holds for certain presentations of scientific propositions, but it is neither necessary or common to science itself. Fichte considers systematic form as only incidental to the activity of science, not its actual essence (EPW, 104). A necessary condition for a science is that the collection of propositions constituting the science are sound. Without soundness at the ground, no matter however systematic or coherent the other propositions might be, there is a failure to reach the level of science. Obviously, a coherent collection of propositions that are false or fail to touch the world, is not, simply because it is systematic, a science.
Systematic form, as Fichte uses the concept, is not meant merely to describe the structure the totality of propositions take, it is also, and perhaps more importantly, a rule or normative condition about how those propositions should be ordered. As a normative condition governing inferences, systematic form is what provides reason to accept one inference over another seemingly valid inference. In other words, the validity of an inference is checked against whether or not the inference is systematic or not.
When it comes to checking the validity of an inference or whether it is systematic, Fichte thinks we must examine how the two propositions are 1) connected to each other and 2) connected to a first principle that is self-justifying and certain. In both cases we are ultimately worried about how one proposition is connected with another proposition, and according to what reasons or principles the rule connecting them is a valid rule. Fichte defines "the form of the science" as the manner or way [die Art] in which we pass on the certainty from the first principle to other propositions. Given these remarks, systematic form is not meant as a descriptive property that characterizes a totality of propositions; it rather refers to a "specific kind of inference by which we infer the certainty of other propositions from the certainty of the first principle" (p. 105). In making this point, Fichte asks what our "warrant" [Befugnis] is for such inferences. First, I want to suggest, somewhat schematically, what the rule of connection might be, and in a separate post I hope to suggest why Fichte thinks it is a good rule. To understand this rule, I think, is to further illuminate what Fichte means by systematic form a logical stance, not descriptive one.
One option I think Fichte provides is what I will call, for the sake of ease, the equivalency criterion. The equivalency criterion says that proposition P is equivalent to proposition P1 iff there is some content in P1 that is also in P. The equivalency criterion does not guarantee that P and P1 are consistent. If a proposition P consists of R and S and is equivalent in respect R to proposition P1 then they seem to meet the equivalency criterion. However, proposition P1 might conceivably consist of R and ~S, which means that though they are equivalent in a certain respect, they are also inconsistent in another respect. For this reason, the equivalency criterion must be supplemented by a consistency criterion. The consistency criterion says that proposition P is consistent with proposition P1 iff there is not some content in P1 that contradicts P.
I take it that the equivalency criterion and the consistency criterion are what Fichte is after when he writes:
[The] sole means for expanding…knowledge and making it more certain would be by comparing what is uncertain with what is certain and then inferring the certainty or uncertainty of the former from its equivalence [Gleichheit] or inequivalence [Ungleichheit] (if I may make provisional use of these terms until I have time to explain them) to the latter. If an uncertain proposition were the equivalent of one that is certain, then it could be safely assumed that it would be certain too. If the uncertain proposition were opposed [entgegengesetzt] by one that is certain, then we would know that the uncertain proposition would be false. The mind would thus be insured against being deceived any further by the false proposition. It would be freed from error, but it would not have gained truth (Fichte, Early Philosophical Writings, p. 102).
Fichte’s terms here could be more exact. The passage articulates a version of the equivalency criterion, but what does it say about the consistency criterion? The consistency criterion I think is what is meant when Fichte says that P and P1 cannot be opposed. The rule for inference making is that the proposition inferred must be equivalent and consistent with some other proposition. This still seem quite vague. In a future post I will attempt to address this issue further.
Fichte, Early Philosophical Writings, (trans.) Daniel Breazeale (Ithaca: Cornell University Press, 1988).