I am quite troubled by a certain singularity in thought which has crept into our common usage. In general, we strive for precision in our words, and tend to inflate and separate words, broadening vocabulary, manufacturing new separate words when we run across ambiguity. Sometimes several disparate concepts are contained in one word and used for one or the other. Context alone guides us to the intended meaning. Sometimes, we allow ambiguity to persist when the disparate meanings have been deeply rooted in our language for a long time. Such things are the business of philology. That confusing preamble having been churned out, I am concerned with our historical use of the word 'probability' and how we have allowed two quite disparate concepts to fuse without a protest - to the clear detriment of clarity of thought. I single out English for this example, for that is my principal language. It may be a similar confusion in the other languages as well. From the original Latin, "probere" is to prove. It gave rise to the words "probative" and "probable," which were originally much closer in meaning, if not identical. Something which is "probable," in the original sense, is that which can be fleshed out into that which is probative, i.e. actually proving. In piddling around with the mathematics of likelihood, and post-hoc methods in exploring empirical association, mathematicians made a grave error in attaching the word "probability" to this study, regrettably wrecking the concept when it left the mathematical field and came into common parlance. Now, in the common parlance, "probability" means primarily the empirical likelihood of a certain event occurring, without reference to its deterministic origins; and also, to a lesser degree, the capacity of a conjecture to participate in a rigorous causal chain of proof. It is not incorrect to look at Euclid's proofs, and say that they are 'probably true.' However, that phrase itself has lost its meaning. (e.g. Federal Rules of Evidence (United States) Rule 401) My philological question is how long ago the term "probability" came into the mathematical language, and also subsequently into the common English language. Do you also see this contradiction? What are the real-life implications?