From: (Steve Hoath) Steven.Hoath@UC.Edu
Help! I need a professional philosophy consult! Can someone tell me what is the "principle of sufficient reason" and how does it figure into the Kantian system? The dictionary (Webster's 3rd International) defines this principle as a "law" such that:
For everything that is
There is a reason why
It should be as it is
Rather than otherwise.
In his proof of the second Analogy in the *Critique of Pure Reason* Kant says:
"The principle of sufficient reason is thus the ground of possible experience, that is, of objective knowledge of appearances in respect of their relation in the order of time." ---(Norman Kemp Smith translation, A201/B246)
My interest relates to the "rule" by which, according to Kant, we determine something in the succession of Time. The principle of sufficient reason is bound up with this rule in a manner which remains indistinct to me. Two other quotes may shed light (or, worse, obfuscate) this question. First, Kant states in the section entitled "The Discipline of Pure Reason in Regard to its Proof" (A783/B811):
"...all attempts to prove the principle of sufficient reason have, by the universal admission of those concerned, been fruitless."
Second, Schopenhauer says in the conclusion of his book *The World as Will and Representation* (Chapter L, Epiphilosophy, in italics):
"...the expression of the most universal and general form of our intellect is the principle of sufficient ground or reason, but that, on this very account, this principle finds application only to the phenomenon, not to the being-in-itself of things, but all whence and why rest on this principle alone."
WHY IS THIS PRINCIPLE SO IMPORTANT?
Enquiring minds want to know.
This won't be as much help as I wish it could be, but in the few moments I have: read the Encyc of Philo on Leibniz. The principle was made famous by him (as satirized by Voltaire in Candide) and it is as as stated in your Webster quote.
I'm not in my office at the moment, but if you'd like more references in Leibniz send me another note and I'll get them. Also, if others on the list don't help connect it to the second analogy, I'll be happy to take a look (my copy of the first critique is also in my office so I can't check the context right now) or recommend some secondary sources.
The reason that this principle is so signficant is, to put it very simply, that we believe that anything that is has a reason why it is, and that with either sufficient reflection and/or investigation (depending upon whether you are an empiricist or rationalist or some mixture) we can always, in principle, grasp that reason. In other words, the principle holds that there must always be a reason that suffices to explain anything that is.
This particular principle is of interest to Kant because his emmediate predessesors (the Wollfians), beleiving that they were faithfully following Leibniz, had the habit of providing proofs for this principle that reduced it to the principle of contradiction. This meant that all truth was ultimately analytic (to use Kant's terminology) or truths of reason (to use Hume's terminology). There only appeared to be truths of fact, or empirical truths, because of the human intellect's limitations on trying to grasp truths of reason. But for Leibniz, and thus the Wollfians too, everything is a windowless monad. There is no real interaction between these and what appears to be causal interaction is merely each monad reflecting the whole world through it own internal principles of development. God created a world with monads whose internal principles of development were consistant with each other, and also such that they constitute the best of all possible worlds. Monads have differing abilities to reflect the world with clear and distinct representations. Humans, of course are the best of any finite monads.
Kant believes in genuine interaction. And because of this, he rejects the Wollfians reduction of the principle of sufficient reason to the principle of contradiction. His clearest presentation of the need to reject the Wollfian position occurs in his New Exposition of Two Principles of Metaphysics (or something like that). Its original title is customarily abbreviated Nova Dilucidatio, since it was written in latin. It is available in Kant's Latin Writings edited by Lewis White Beck.
Kant rejects the Leinizian-Wolffian project of reducing all truth to the principle of contradiction. In doing so, he is also rejecting the Leibnizian view that there is no such thing as real interaction. The Libnizian-Wolffians are trapped within a system that only allows them to analyze the the relations between concepts. They cannot, indeed they do not, wish to discuss the real relation among things. For them there really are things but those things are not in real relation to each other.
For Kant the principle of sufficient reason was the principle that guaranteed the real relation of every object to every other. Very breifly, Kant holds that sensible intuitors with discursive understandings are constrained to think real relations in terms of cause and effect. In its most abstract form (the unschematized categories) this amounts to thinking in terms of real ground to real effect without specification of the aesthetic nature of the ground and effect. But since we humans are also spatial-temporal intuitors, the particular manner in which we must experiencethe relation of real ground to real effect is that of temporal cause to temporal effect. The second anaolgy holds that everything that happens in time (temporal effect) is necessarily caused by some thing (i.e. some temporal ground). In other words, the second analogy is the particular manner in which spatial temporal intuitors with dicursive understanding are constrained (necessarily) to think of real relations. His rejection of Wolff is also a rebuttal of Hume's scepticism with regard to the principle of cause.
[Trans. G. Montgomery, rev. A. R. Chandler, from the French] "31. Our reasoning is based upon two great principles: first, that of Contradiction, by means of which we decide that to be false which involves contradiction and that to be true which contradicts or is opposed to the false.
"32. And second, the principle of Sufficient Reason, in virtue of which we believe that no fact can be real or existing and no statement true unless it has a sufficient reason why it should be thus and not otherwise. Most frequently, however, these reasons cannot be known by us."
The principle of causality, for Kant, is the principle by which one event necessarily follows another in time. It cannot be proved by the Principle of Contradtion. It is a version of the Principle of Sufficient Reason. Kant thinks that we must use the principle of causality in order to distinguish between what is objective and subjective. See Hume's discussion of the causal principle, which Kant studied.