In this master thesis, the ethical mutual fund (respectively socially responsible investing- or SRI-fund, as this financing movement is often called and abbreviated) debate, which is backed up by a growing body of scientific literature, is critically examined. On doing so, three important foci of this academic text can be identified. First of all, the existing research is identified to be centered upon the performance of SRI-trusts, while mostly ignoring the ethical and moral dimensions of ethical investment. As this ethical and moral dimensions seem to be of incredible importance when searching for the raison d?être of this financing movement, this master thesis will, amongst other things, concentrate on this aspect. Secondly, as there have been many empirical studies on the performance of ethical mutual funds, this master thesis will try to sum up the most robust insights of those studies. Thereby, studies regarding various countries, different periods of time and different methods of measuring performance are tried to be summed up conclusively. Thirdly, this master thesis tries to identify further differences between conventional and ethical mutual funds by looking at the motivations of investors and the underlying economic theory and definition of those funds. All in all, this master thesis tries to answer the following research question: Is it possible to reasonably distinguish ethical from conventional mutual funds, not only critically assessing the performance, but also the mode of operation, investors? motivations and last but not least the ethical and moral justification of SRI-funds? This text finally concludes that ethical fund managers have to increasingly focus on the previously neglected ethical and moral dimensions of SRI-funds to sustainably create a plausible distinctive feature in comparison to conventional funds and to prospectively mature from an investment niche to a more widely recognized investment alternative.