...and inside mathematics there is only probability
Just because there is truth in mathematics doesn't mean there can be no other truth.
Equally, the truth in mathematics is not limited to probability (in any sense). The truths in mathematics are absolute and not limited to the field of probability.
OK I mean social truth, in society compared to the social sciences, we call that in Dutch sociology, so in society versus sociology => statistical research in sociology gives only probability, in society people talk and behave what is the most appropriate for their situation (i.e. what serves their interests best), OK not always, but in general
That's a hugely restricted context that isn't hinted at in your original statement. I understand what you are saying, but I could still argue against it in that the mathematics of statistics is a collection of true and provable theorems. What is crucial in statistics is the interpretation of the results, which should usually be much more qualified than people would like.