Opportunity and opportunism are kaleidoscopic words, as revealed in scholarly works. That pluralism is due to the variety of approaches, studied in this essay according three angles: semantic, historic, and pragmatic. Firstly, the Greek and Latin roots enlighten the alternative impact of three basic behaviours – hubris, metis, phronesis– on opportunity, as an intent, and opportunism, as a practice. The second part refers to the both “history” and “stories”. Early theorists on French entrepreneurship reveal differentiated versions of opportunism, supported either by realistic stories, as novels by Balzac, or by actual cases, as the Digicode story. The third part prioritises the opportunity as a pragmatic and cognitive process, based on the own perceptions of entrepreneur, viewed as an idiosyncratic people. Consequently, opportunity is not appraised, either as a hazardous “windfall event” ( a “flash of genius”), or as a determinist discovery of “hidden markets”. It must be assumed to result from conscious, or even unconscious processes, linked to past events and culture of each entrepreneur.