Cf. Baltzer, Christologie, p. 10 f., Schwane, p. 272 f. Other explanations which have been suggested are quite inadmissible. Dorner, p. 407, takes the passage cited above about ‘substance’ too seriously, and wavers between the equally impossible interpretations of ‘countenance’ and ‘personality.’ Förster (l.c. p. 659) understands the word to mean ‘mode of existence.’ Wirthmüller, cited by Schwane, p. 273, has the courage to regard ‘form of God’ and ‘form of a servant’ as equivalent to Divinity and humanity.