著者
沢田 允茂
出版者
慶應義塾大学
雑誌
哲學 (ISSN:05632099)
巻号頁・発行日
vol.35, pp.121-139, 1958-11

伝統的論理学では論理学の最高原則又は原理として同一律、矛盾律、排中律等を挙げていることは衆知の事実である。しかし同時に現代の数学的論理学に於いてはこのような原理は唯一の公理の組ではなくて、せいぜい他の多くの論理規則の中の二三のものとして加えられるに止まり、従って論理学の原理とか原則などと云う概念そのものさえ余り用いられていないことも明かなことである。しかし過去の多くの哲学体系の中には明瞭に同一律、矛盾律、排中律等の論理学の原理が哲学の出発点となっている場合が多いし(例えば肯定的な意味ではフィヒテ、否定的な意味ではヘーゲルを挙げることが出来るであろう)、又論理学と対象界との関係が問題になる場合にはある意味に於いて右の原則の解釈が中心的な地置を占める場合が多い。従って右の原則は論理学プロパーの問題に属すると云うよりはむしろ認識論的な議論に属すると見ることが出来る。しかし従来それらがいはゆる論理学の原理と考えられていた所に実は論理学と認識論との、はっきりと区別し難い哲学的問題が指摘され得ることも見逃すことは出来ない。この小論文では(1)これらの原則の論理学内に於ける表現の仕方自身がすでにある哲学的、認識論的立場を先取していること、(2)これらの原則のある特定の解釈から生じている哲学的立場の批判、及び哲学的、認識論的問題として如何にこの問題を解決すべきかについての或る意見を述べることとする。
著者
沢田 允茂
出版者
慶應義塾大学
雑誌
哲學 (ISSN:05632099)
巻号頁・発行日
vol.34, pp.B53-B82, 1958-01

小林澄兄先生古稀記念論文集There are, among others, four expressions which bear some resemblance to each other though they are not identical. They are: 'There is.....', '.....exist', '.....is a reality' and '.....is a fact'. The expression '.....exist' to which the term "existence" is a corresponding noun has some ambiguities: sometimes it is used to mean 'There is.....', another time to mean '.....is a reality'. The expression 'There is.....' is quite popular and sound. Existence in this sense is neutral, that is to say, it has no particular ontological commitment; it is rather a matter of linguistic decision. From a linguistic point of view (and from a view-point of formal logic also) we can talk about anything - about physical objects as well as about numbers and imaginary things). Problems of "ontological commitment" or "abstract entities" which have recently been widely discussed by logicians like Quine, Carnap etc. have, in fact, nothing to do with the so interpreted use of (Ex) of the contemporary formal logic. What is then the linguistic decision of the expression 'There is.....'? The expression is used either 1) to make ourselves assured that the thing we are going to state is worth while (minimum evaluative presupposition or pragmatic motive of our linguistic activities) or 2) to make others pay attention to and to "assure them" of the fact that the thing they are going to be told is worth while (appeal to others). The use of 'There is.....' is not purely cognitive one; it is rather performatory. What is said to be existing is what is refered to by "x" in 'There is x.': physical objects, theoretical constructs, numbers or imaginary things as well - not the existence of these things is said to be existing. Existence itself, though it has a fact-stating aspect in each particular instance of its use (like "good" in "good apple" and "good automobile" has its descriptive aspects, in each case in a different sense), can not be concieved as meaning something like an independent object of our cognition; only objects of our cognition are the things said to be existing. Nor can we talk of "existence in general" as an object of ontological arguments because what we can generalize is nothing but a universality of that assuring activity itself. The concept "Reality" will be interpreted as meaning "true existence" and thus not as referring to any cognitive object but rather as an appraisal of a certain kind of things as well as the assurance of its being worth while. The adjective "true" as appraisal has a role of selecting, according one's own preference, a certain kind of things as more valuable to talk about than any others. The question of what is reality, therefore, depends upon one's own preference rather than upon anything cognitive. The expression '.....is a reality' is, then, a stronger way of ascertsining whatever that is said to be existing than that of merely saying that there is such a thing. While expressions like 'There is.....' or '.....exist' are used to give assurance of the thing we are going to state, the expression '.....is a fact' is used to mean something about what is stated already. Hence it bears something cognitive comparable with truth and falsity of statements. The fact has its structure which is expressed in the common expression like 'the fact that....'. What is, then, the nature of this structure? The situation is very much similar to the problem Kant had once pointed out when he talked of our experiences being constructed by some a priori principles. The difference is that we regard these principles not as of an a priori nature but merely of a linguistic one. The structure of fact is determined by a collaboration both of the structure of the objects and of that of the language we talk about these objects.