The race of men is capitalised, so man=male and Man=the race.

‘Hinder me? Thou fool. No living man may hinder me!’ Then Merry heard of all sounds in that hour the strangest. It seemed that Dernhelm laughed, and the clear voice was like the ring of steel. ‘But no living man am I! You look upon a woman. Éowyn I am, Éomund’s daughter. You stand between me and my lord and kin. Begone, if you be not deathless! For living or dark undead, I will smite you, if you touch him´

Notice the lack of capitalisation in Witch-King's quote