SUMMARY
The phenomenon of slavery existed throughout the entire period of the ancient world and met with interest from both Greek and Roman philosophers. Despite the emerging views of various philosophers criticizing slavery as a social phenomenon, no theory of slavery was formulated then. The philosopher who-, in both his works and correspondence, included numerous references to the situation of slaves and the institution of slavery was M.T. Cicero. Searching for humanism in Cicero’s views on the above-mentioned issue, attention was drawn to the principles of the Stoic doctrine, within which the concept of human freedom was formulated, and to the essence of natural law. These concepts made it possible to analyse the discussed problem in the context of the words of Terence Homo sum, humani nihil a me alienum puto. And as regards humanism in Cicero’s views, it is evident when he recognizes a human being in a slave; when he says that the principles of justice must be observed towards people from the lowest rank, which is the rank of slaves; when he firmly states that slavery is among the worst things that can happen to the human being. On the other hand, we see Cicero’s completely different views on slaves when he talks about punishing slaves, „keeping a tight rein on them,” or „destiny by nature for the best to rule others, and with great benefit for weaker beings”; also when he emphasizes his negative attitude towards the liberation of slaves. To conclude it should be emphasised that this characteristic feature of Cicero, namely his lack of uniformity of views on various philosophical doctrines, which we can also find in his views on slavery and the rank of slaves, does not prevent us from seeing a humanist in Cicero who, with his sense of justice, advocating the stoic doctrine and the principles of natural law, moved very slowly towards the stoic moral philosophy and all the ethical principles that Christianity would bring.