Probability has become one of the most characteristic concepts of modern culture, and a 'probabilistic way of thinking' may be said to have penetrated almost every sector of our intellectual life. However it would be difficult to determine an explicit list of 'positive' features, to be proposed as identification marks of this way of thinking. One would rather say that it is characterized by certain 'negative' features, i. e. by certain attitudes which appear to be the negation of well established traditional assumptions, conceptual frameworks, world outlooks and the like. It is because of this opposition to tradition that the probabilistic approach is perceived as expressing a 'modern' intellectual style. As an example one could mention the widespread diffidence in philosophy with respect to self -contained systems claiming to express apodictic truths, instead of which much weaker pretensions are preferred, that express 'probable' interpretations of reality, of history, of man (the hermeneutic trend). An analogous example is represented by the interest devoted to the study of different patterns of 'argumentation', dealing wiht reasonings which rely not so much on the truth of the premisses and stringent formal logic links, but on a display of contextual conditions (depending on the audience, and on accepted standards, judgements, and values), which render the premisses and the conclusions more 'probable' (the new rhetoric).