well, I meant that, technically, Modern Greek relates to Ancient Greek in the same way as Italian relates to Latin.
thus, it's illogical to claim Modern Greek is the same language as Ancient Greek if we claim that Italian isn't the same language as Latin.
we should either postulate that both (and any other languages for that matter) represent the same continuity, or that both are separate from their ancient forms.
or, as it seems to me more productive, we should insist on the relativity of the notion "same/different language" on a diachronical level in the same way linguists say it is hard to determine it on a synchronical level, e.g. in the case of "language/dialect" distinction.
but those are indeed random thoughts which are completely off-topic here.