The problem of the proof weight is one of the most intricate and disagreeable issues, because
of the dissonance of opinions as to its nature and non-linearity in the scope of terminology.
Starting from the 1950s, namely from the changes introduced to the Committee of the civil procedure
code from 1930 by means of the legislation from 20 July 1950, there was a claim in the Polish
science built on an ideological ground, negating the value of onus probandi in the civil matters. After
the reform from 20 July 1950, the Polish court law was the law of a specialist type, based on different
ideological assumptions and against the so far existing bourgeoisie law. Following the Russian
doctrine, the legitimacy of differentiating the private from the public law was negated. And,
consequently, different ways of shaping the civil and criminal process. In so doing, the legacy of
the former civilization was put away. At the same time, the importance of the objective truth in
the civil trial as its fundamental rule was emphasized, and the action of the court ex officio was
When the influence of ideology on the court law weakened in the 1960s and 1970s, the usefulness
of onus propandi in the civil proceeding was no longer questioned.