We don’t know .each other except by the signs, the words, which enable us to communicate and to have a common activity. Now this, of course, was another anticipation of the life of the technical society in which we are existing, which developed first of all in those countries in which nominalism was predominant, as in England and in this country The attitude of the relationship between man and man, between man and things, is nominalistic, in this country in the traditions of American philosophy, as it is largely in England and in some Western European countries. The substantial unity which was preserved by realistic thinking has disappeared.
Now this means that we have knowledge of the others not by participation but only by sense perception – seeing, hearing, testing: it’s always a form of sense relationship. This refers to all our reality, but it doesn’t mean that there is a world of essences, in which our mind a priori participates. We deal with our sensual intuitions and the ref lections of it in our mind. This of course produces positivism: we have to look at what is positively given to us. From this many things follow: Irrational metaphysics is impossible. For example, it is impossible to establish a rational psychology which proves the immortality of the soul, its pre- or post- existence, its omnipresence in the whole body. All this is, if it is affirmed, a matter of faith but not a matter of philosophical analysis. In the same way, all sides of rational theology are impossible. God does not appear to our sense apperception.
Therefore since we have no direct immediate relationship to it as we have in Augustinian thinking, He remains unapproachable. We cannot have direct knowledge of God. We can have only indirect ref lection, but ref lections, discourse, never leads to certainty but only probability, of a lower or higher degree. And this probability never can be elevated to certainty, and even its probability is doubtful. It is quite possible that there is not one cause of the world, but different causes. The most perfect being – -which is the definition of God – is not necessarily an infinite being. A doctrine like the Trinity which is based on mystical realism –the three personae participate in the one Divinity – is obviously improbable. They all, therefore, are matters of irrational belief. Science must go its way and faith must guarantee all that is scientifically irrational and absurd.