Style guides seem to agree that words referred to as words should be italicized or set in quotes. So:
- The term critical mass is...
The CMOS 17th adds that proper nouns used as words are usually set in roman, giving this example:
- You rarely see iPhone with a capital i. (Section 7.63)
I'm wondering more generally about references to names. Does it make sense to leave all the following names in roman?
Two men, both named Sam, were...
His name was Sam.
Call me Ishmael.
The girl called herself Peggy, though her name was Margaret.
She referred to the drink as a Manhattan Project and ordered two.