The given statements use the quantifier 'Some'. 'Some men are great' means there is an overlap between the sets of men and great people, but it doesn't exclude the possibility of men who are not great. Similarly, 'Some men are wise' implies an overlap between men and wise people, but not exclusivity. Therefore, we cannot conclude that all men are either great or wise (Conclusion I), nor can we definitively say that some men are neither great nor wise (Conclusion II). The premises do not provide enough information to establish either of these conclusions with certainty.