It has always been the ideal of science to discover laws of nature on which we can all agree. Agreement requires evidence independent of individual judgment, i.e., objective evidence. We apply the term objective to such unbiased scientific evidence because we associate it with an external world of objects that we conceive to be the origin of our information. This external world is instinctively invented by each of us as a means of dealing with invariant patterns in his private world of experience. The invention is validated and elaborated as a consequence of the fact that it turns out to be sharable. In fact the common content of all our invented external worlds is so unambiguous and independent of individual bias that it can form the universally accepted basis for communication and action in an organized society. The consistency of the patterns of experience associated with the external world is such that we are under severe psychological compulsion to assign to this world an existence independent of our experience and a reality superior to that of any small part of our experience. Physical science is devoted to the study of the “laws” of the external physical universe, i.e., to the behaviour of the objects in it. Hence there is a strong tendency to project into the external world the information gathered by scientifically objective methods and even the theoretical concepts in terms of which the information is interpreted. Whatever is so projected is objective in a second sense of the term, i.e., assigned by us to the external world of objects.

A quarter of a century has elapsed since quantum mechanics was discovered. Perhaps it is not too much to say, in retrospect, that the time was ripe for this particular development. This is attested, not only by the speed with which the edifice of the theory was completed immediately following the basic discoveries of Heisenberg and Schrödinger, but also by the rapidity, well-nigh unprecedented in the history of science with which the new results were applied to almost every branch of physics and chemistry. A mental readiness on the part of the scientists involved might have had much more to do with this than the facilities of modern communication systems.

The two most antagonistic schools in contemporary Western philosophy are Existentialism and Logical Positivism. They have nothing in common but the name of philosophy, and even that they deny each other. There is some kind of discussion going on between even such distant schools as Pragmatism and neo-Thomism; Existentialists and Logical Positivists have nothing but sarcasms for each other. To philosophers familiar only with the Anglo-Saxon scene Existentialism must appear negligible. In the Mediterranean countries, on the other hand, where philosophy is a much more popular pastime, Existentialism has an unparalleled vogue and Logical Positivism is considered a horrible aberration from the naturally speculative course of philosophy. In South America whose philosophical life we are apt to underrate Logical Positivism seems to be known to almost nobody, whereas Existentialism, mostly in its German and anti-religious shape, has become, quite paradoxically, the rallying point of “Liberalism,” liberalism, in Spanish countries, being above all anti-catholicism. Although, ironically enough, both Logical Positivism and modern Existentialism originated in German speaking countries, the split between the two goes vaguely parallel with, and may have found some ready echo in, the different cultural inheritance of the Anglo-Saxon and Latin races. Hence, the subject of this paper would seem far-fetched to those steeped in their own national tradition. There is, however, a growing consciousness of the “one world” function of philosophy, particularly with regard to Eastern and Western philosophy (Northrop, Burtt, Conger, etc.). Would it not be a prerequisite of this more ambitious enterprise to gain a clear conception about the most radical split in our own contemporary Western philosophy, the split between Logical Positivism and Existentialism? This paper is an attempt to establish a perspective permitting a just evaluation of the two philosophies.

Among the many dichotomous cleavages among philosophers and theologians few seem to me as questionable as the Procrustean division into supematuralists and naturalists. “Naturalism” and “supernaturalism” have become party labels whose original meanings have been lost in the heat of banner-waving and slogan shouting. Even the great minds of the past, who were innocent as yet of this philosophical two-party system, are being herded into one pen or the other. And apparently few of the penkeepers are aware of the fact, pointed out almost apologetically by Professor Randall, that “the usage is hardly fashionable abroad, even in England.” (39, p. 355) I, for one, confess that, not having been acclimatized in my European cave to this stern disjunction, I have to this day felt rather uneasy, if not evasive, at the outspoken or tacit expectation to line up with one faction or the other, much as my leanings were toward the other rather than toward the one. I therefore decided that some day I had to get to the bottom of this uneasiness.