Intrinsic validity of contracts - lex loci voluntatis; lex loci intentionis

According to Paras, it should be noted that while the first paragraph of Art. 17 speaks of forms and solemnities, no mention is made of the law that should govern the intrinsic validity of contracts in general. The prevailing rule in Private International Law today is to consider the lex loci voluntatis (the law of the place voluntarily selected) or the lex loci intentionis (the law of the place intended by the parties to the contract).