The following is an English translation of the 1960 paper by the South African philosopher D. C. S. Oosthuizen entitled "Die Transendentaal-Frenomenologiese Idealisme: ‘n Aspek van die konstitusie-probleem in die filosofie van Edmund Husserl," preceded by a few contextualizing remarks by the translator. The paper attempts to show that the phenomenological, eidetic and transcendental reductions, the problem of constitution and transcendental genesis are indispensable parts of the transcendental phenomenological method. It then demonstrates that this method and the results that are obtained by means of it cannot, strictly speaking, be said to decisively favour a metaphysical or epistemological idealism, specifically because the transcendental reductions cannot be undone.