Facts
The appellant [E.A.] and the respondent [M.A.] are divorced spouses with two daughters, [X.] (born 1988) and [Y.] (born 1990). In April 1999, [M.A.] filed a lawsuit for divorce and requested provisional measures. The President of the District Court of Baden ordered that the children be placed in the custody of the mother for the duration of the proceedings and determined [E.A.] 's maintenance obligation.
In May 2000, [M.A.] filed a request for marital protection measures and demanded, among other things, that it be established that she was entitled to separate living and that the two girls be placed in her custody. [E.A.] opposed the request for separate living and, in the alternative, requested that custody of the daughters be awarded to the parent whose care would best ensure their well-being.
The High Court (5th Civil Chamber) of the Canton of Aargau dismissed the appeal, with which [M.A.] had requested higher maintenance contributions, in its entirety. To the extent that [E.A.] had requested a reduction in maintenance contributions, his appeal was partially granted. His request to place daughter [X.] in his custody for the further duration of the separation was also rejected.
Considerations
The Federal Court dealt with the question of whether the High Court, by rejecting a repeated hearing of daughter [X.] , violated Art. 144 CC, Art. 9 and 12 of the UN Convention on the Rights of the Child, the principle of investigation, and the prohibition of arbitrariness (Art. 9 Cst.) and the right to be heard (Art. 29 para. 2 Cst.).
The court found that the obligation to hear the child as an instrument of fact-finding was not violated. The question of whether the obligation to hear the child was violated ultimately coincides with the question of a possible disregard of the federal law principle of investigation inherent in Art.…