In the field of the Philosophy of Science, the debates between realism and positivism develop into major concerns. This article intends to expose the nature of this development and address the issues arising form it. Thus, even though we have selected several figures representing this development, the core of this exposition is not therefore ‘historical’, but ‘thematic’. We attempt to illustrate the themes developed form realism of scientific practice and the anti-metaphysical positivism. These them include that of ‘reality’, ‘truth’, ‘theoretical entities’, ‘the given of experiences’, ‘observations’, ‘the empirical aequacy’, etc. Through analyzing these themes, we conclude that, with regard to the question ‘Is science true?’, racism and positivism should be considered two modes of description which cannot be compared on the basis f objective criteria.