Thesis (PhD)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: This dissertation is a critical analysis of the significance that the anhypostasis and enhypostasis of Christ’s human nature play in Karl Barth’s Christology. It does so in five parts. First, this dissertation examines the historical orthodox understanding of the concepts anhypostasis and enhypostasis to explain the human nature of Christ, and defend the Chalcedon definition of the two natures in the patristic, scholastic, and post-scholastic periods. Historically, orthodox writers consistently express anhypostasis and enhypostasis as autonomous concepts, where enhypostasis refers to the reality of Christ’s human nature in union with the Logos, and anhypostasis expresses Christ’s human nature as having no subsistent reality outside its union with the Logos. Karl Barth appropriates anhypostasis and enhypostasis as a dual formula to express the humanity of Christ, which moves beyond historical orthodoxy and is unique to his Christology. Second, this dissertation evaluates Karl Barth’s unique interpretation of the anhypostasis and enhypostasis of Christ’s human nature as a dual and congruent formula to express how the humanity of Christ exists in union with His divine essence. Third, this dissertation follows the historical development of anhypostasis and enhypostasis in Karl Barth’s Christology and its ontological function in Barth’s development of the revelation of Jesus Christ as the ‘Word became flesh’. In his break with liberal theology Karl Barth emphasizes that the revelation of God is made manifest exclusively in the person of Jesus Christ, which is ontologically grounded in the anhypostasis and enhypostasis of Christ’s human nature. Fourth, this dissertation identifies the themes of coalescence between the divine and human natures of Christ where Barth expresses Christ’s human nature as anhypostasis and enhypostasis in His role as the mediator of reconciliation between God and humanity. Fifth, this dissertation evaluates Barth’s critique of Chalcedon’s definition of the two natures expressed through the anhypostasis and enhypostasis of Christ’s human nature. While Barth does not disagree with Chalcedon, he desires to express more precisely the union of divine and human natures in Christ as the act of God’s revelation, as the Son of Man, in His exaltation. / AFRIKAANSE OPSOMMING: Hierdie verhandeling is 'n kritiese analise van die belangrike rol wat die anhypostasis en enhypostasis van Christus se menslike natuur in Karl Barth se Christologie speel. Die studie bestaan uit vyf gedeeltes. Eerstens ondersoek hierdie verhandeling die historiese ortodokse verstaan van die konsepte anhypostasis en enhypostasis om die menslike natuur van Christus te verduidelik, en die Chalsedoniese definisie van die twee nature in die patristieke, skolastiese en postskolastiese periodes te verdedig. Histories gebruik ortodokse skrywers anhypostasis en enhypostasis deurgaans as outonome konsepte, met enhypostasis wat verwys na die realiteit van Christus se menslike natuur in gemeenskap met die Logos, en anhypostasis wat verwys na die wyse waarop Christus se menslike natuur geen bestaansrealiteit los van hierdie gemeenskap het nie. Karl Barth gebruik beide anhypostasis en enhypostasis as 'n tweeledige formule om uitdrukking aan die menslike natuur van Christus te gee en gaan hiermee verder as die historiese ortodoksie posisie, wat 'n unieke eienskap van sy Christologie is. Tweedens evalueer hierdie verhandeling Karl Barth se unieke interpretasie van die anhypostasis en enhypostasis van Christus se menslike natuur as 'n tweeledige en kongruente formule om te verduidelik hoe die menslikheid van Christus in samehang met Sy goddelike wese bestaan. Derdens volg hierdie verhandeling die historiese ontwikkeling van anhypostasis en enhypostasis in Karl Barth se Christologie en die ontologiese funksie wat dit in Barth se ontwikkeling van die openbaring van Jesus Christus as die ‘Woord wat Vlees geword het’ verrig. In sy breek met liberale teologie beklemtoon Karl Barth dat die openbaring van God uitsluitlik in die persoon van Christus voorkom, en dat hierdie openbaring ontologies in die anhypostasis en enhypostasis van Christus se menslike natuur gegrond is. Vierdens, identifiseer hierdie verhandeling die temas van vereniging tussen die goddelike en menslike nature van Christus, waar Barth Christus se menslike natuur as anhypostasis en enhypostasis in Sy rol as bemiddelaar van versoening tussen God en mens beskryf. Vyfdens evalueer hierdie verhandeling Barth se kritiek op die Chalsedoniese definisie van die twee nature, wat uit sy verstaan van die anhypostasis en enhypostasis van Christus se menslike natuur voortspruit. Terwyl Barth wel Chalcedon aanvaar, wil hy graag op meer presiese wyse die eenheid van goddelike en menslike nature in Christus, as die handeling van God se openbaring as die Seun van die Mens in Sy verheerliking, beskryf.