What authorities existed for people of mental labor in the Middle Ages?

For theologians – Holy Scripture and the Holy Fathers, for geography – Ptolemy, for medicine – Hippocrates, for physics – Archimedes, for philosophy – Aristotle.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.