The aim of this paper is to analyse the link between understanding another person and understanding the Self in Joseph Conrad’s Heart of Darkness – a complex novella which raises a whole array of themes connected with human nature and the consequences of the lack of an established frame of reference. In a world where individual subjective consciousness appears to be not only the basic means of cognizance, but also the sole judge, Man is isolated from others and overwhelmed by the dark forces which seem to govern a hostile universe and also his own nature. The possibilities of arriving at any conclusive truths and achieving genuine communication with others are severely limited. However, the disquieting awareness of mortality, the darkness inherent in human nature, the apparent hostility of the universe, the dire lack of universal absolutes and the relativism and scepticism which result from all these circumstances do not in any way exempt us from the moral obligation to at least strive to fulfil the injunction “Know thyself!” – as it is self-delusion that Conrad abhors most of all. In order to overcome these difficulties and existential dilemmas, he proposes a set of simple principles concerning work, discipline, self-restraint, honour, solidarity and human interdependence, for it is usually because of others or in others that we realize the truth about our own nature.