Hi Aleksandar
I would not call von Weizsäcker a platonist. But he surely knows Plato very good and thinks, that the main philosophical questions have already been posed in Platos work. In his book 'Time and Knowledge' he referenced Plato in more then 100 pages. Kant only 70.
My view (and this became much clearer to me in the discussions in the forum) is more that objective knowledge must be mathematical. In my essay I try to avoid discussions about ontology and reality as much as possible.
I hope you'll read my essay and leave a comment on it, although I had too little time to write it and develop a clear path of reasoning.
Best regards
Luca