A man cannot inquire either about which he knows, or that which he does not know. For if he knows, he has no need to inquire, and if he does not, he cannot. For he does not know the very subject he is to inquire.
Socrates’ response:
(1) The soul is immortal.
(2) All learning is recollection. (Nothing can be taught, only remembered)
(3) So, man learns through the soul’s recollection…there is nothing the soul does not already know. The paradox is mere sophistry.
Is Socrates right?
writer, researcher, editor 
is Socrate’s second statement based on the idea that man cannot inquire about which he does not know? i’m not sure i understand the relationship between your first paragraph and socrates’ response.
my response, however, is that of course man can inquire about which he does not know, or at least about what he does not know completely, but has SOME idea about. man’s brain is not a machine that simply outputs what is inputted. rather, it can create, synthesize, and imagine. altho man cannot inquire about something which he has ABSOLUTELY no basis for knowing whatsoever, he CAN inquire about something of which he has SOME idea, but not complete knowledge. so perhaps there is no completely brand new idea, but rather only the putting together of and building upon old ideas, but putting together and building upon produces ideas that seem very new and completely unknown to ideas previously known.
in the same vein, man CAN inquire about which he does know, or again, at least about what he does not know completely, but has some idea about. and this would basically apply to everything because there is no topic about which a person can know every possible thing because there is always the potential for the connection of ideas that have yet to be put together. so as they say, “the possibilities are endless,” but it is this inquiry about that which we know (somewhat) that leads to innovation.