Scepticism is the questioning of given facts and opinions and has proven to be a dangerous practise in some cultures. We only have to think of Giordano Bruno’s fate (burning at the stake) and the threat of it to Galileo to appreciate the danger. Whilst scientific scepticism is the foundation of progress in our modern world and is generally regarded as a good thing by society, religious scepticism can appear to challenge religious authority and that can be fatal.
In the fourteenth century, the French theologian Nicholas of Autrecourt [c 1299-1369] developed scepticism on the basis that it was right to question beliefs that were not primary, that is, fundamental. He would not have denied the existence of God, for example, but he questioned common assumptions about the structure of space and time. He considered that matter, space, and time were made up of discrete parts, that is, atoms, points, and instants respectively. He went further and attempted to explain the processes of change, that is, regeneration and decay, as due to rearrangements of these discrete constituents.
Nicholas had an empiricist view of knowledge. According to one analysis,
Nicholas laid it down that the sole sources of certitude are the immediate data of consciousness and the law of non-contradiction . . . and every certain conclusion must be deduced from principles firmly and exclusively based on evidence which only the immediate data of consciousness can supply. [Weinberg, 1942]
Although to us his scepticism was primarily scientific, it was seen in his day as religious scepticism and so he was forced by the Church authorities to recant and burn his writings.