Historically, the problem of discovery or the problem of the genesis of scientific ideas has been taken seriously by the historians, psychologists, sociologists and philosophers who analyzed the creative thinking and formation of ideas and attempted to provide a meaningful account of them. In fact, the philosophical concern with scientific discovery is as old as science and philosophy of science themselves. However, almost throughout the first half of 20th century, philosophical reflection on the phenomenon of scientific discovery remained in a state of suspended animation. This is because the dominant trend in philosophy of science in this period outlawed it. The dominant view in philosophy of science maintained that the phenomenon of scientific discovery is philosophically irrelevant, and an adequate philosophical understanding of science should confine itself to the way in which scientific theories are justified; it was assumed that the process of justification is a neat, spick-and-span phenomenon eminently suited to be described in terms which are, logically speaking, cut and dry. The process of justification or evaluation according to this orthodox view constitutes the essence of science. Obviously, justification was demarcated from discovery. Justification, because of its supposed epistemic transparency, became the exclusive focus of philosophical attention to the detriment of discovery. The invidious distinction between discovery of scientific ideas and justification of finished ideas of science remained the catchword for a long time. This paper is an attempt to critically examine the nihilistic attitude of the dominant philosophies of science and to arrive at a philosophical theory of scientific discovery.