>(OT Latin: faciem illius agnosco -> "I recognize that
>man's face", but does anyone know how to say "I SHOULD
>recognize that man's face" in Latin?  I'm not familiar
>enough with the language to know it off hand and I
>can't seem to figure it out from my scanty Latin
>reference material.)

I was waiting for someone else to speak up, since I know that we have a
couple of experts in Latin on the list, but, since no one else has, I've
gotten my Latin reference grammars out, and I'll take a stab at it.

 From what I remember (and my reference material seems to confirm this),
you need to use the future passive participle (this is the one ending in
-ndus) together with a form of esse in a construction called the Second
Periphrastic or Passive Periphrastic.  (I've no idea what the first
periphrastic is, nor ever have.)  This "impl[ies] obligation, neccesity, or
propriety (ought or must.)"  (Allen and Greenough's New Latin Grammar for
Schools and Colleges)  ("New" here is a relative term; the original
copyright is 1888, and what I have is a revision of that - still well
before my parents were born.)  My high school Latin book tells me that "the
person upon whom the obligation rests is in the dative."  (Latin for
Americans - Book Three)

Given that information, I think that the sentence that you are looking for
is this one:
Mihi facies illi est agnoscenda.

Somebody, *please,* *please,* *please* pe kind enough to correct my Latin,
because I couldn't find a gender for "facies" but it appears to be fifth
declension, and my first year book was polite enough to inform me that
those are nearly all feminine.  I'm sure I must have gotten something or
other wrong in the sentence.