What is a dream? What difference is there between reality and the images that appear to us during the night while we are sleeping and our body is resting?

Since ancient times, Man has asked himself about the meaning of dreams and on what the confines between dreams and reality are.

Among the many studies made on this topic are three of interest, taken from the past, which highlight how the study of dreams was important even for those who should have had a completely different mentality - meaning mathematicians, scientists, philosophers and members of religious orders

Gerolamo Cardano (1501-1576), a versitile man of the Italian Renaissance, was a famous scientist, mathematician and doctor.

He worked very much in the field of algebra, elaborating a method for resolving particular types of equations and calculations. In the scientific field, we must consider him the inventor of the combination lock, the cardanic suspension (a mechanism that is a support for compasses or gyroscopes) and the cardanic joint (a device which permits the transmission of rotary motion from one axis to another with a different angle. The cardanic joint is still used in automobile manufacturing today).

But if we examine Cardano's writings, we'll find a four-volume piece, written in 1562, dedicated to the explanation of "insomnia and dreams".

His theory of dreams is an analytical exposée, explained logically and written in an engineer's style.

Cardano illustrates a theory on dreams which could be similar to an encyclopedia on the topic. The first part is theoretical: what are the causes of dreams, what types of dreams are there and how can they be interpreted.

The second part is like a consultation manual for those who want to interpret their dreams, and many dream examples are described.


The French mathematician philosopher René Descartes (1596-1650), known in Italy as Cartesio, is considered the founder of modern mathematics and philosophy. He is the man who created the new "method" for scientific research.

This "method" foresaw the application of "scientific thought" for every problem and refused approximated, imperfect, fantastic, ideological and religious notions that were a common part of knowledge at that time.

The "method" has four rules.

  • The first is evidence, no doubts, just proof.
  • The second is analysis, which means dividing the problem up into various separate elements and resolving them starting with the easiest parts.
  • The third is synthesis, whereby you pass from the easiest knowledge to the more complex.
  • The fourth is enumeration and revision, which is done in order to organize the knowledge gained.


Descartes was a man we could therefore consider to be an example of logic and rationality. Yet ...

Yet this scientist and mathematician writes in his diaries that, the idea for his method, didn't come to him while he was awake, while he was thinking or studying, but came to him in a dream, and he even recorded the date. It was November 10, 1619, Descartes was 23 and was in Germany, when he had, during a dream, a revelation for " a completely new type of science", and, from that moment on, he began to elaborate his theories.

Starting from this historical fact, we can think that the confines between reality and dreams, by using that same "scientific method" lead to the land of doubt.

Maybe for this reason, Descartes afterwards wrote, "what happens in a dream does not seem as clear and distinct as that which happens while awake. But thinking on it, I remember having often been tricked, while I was sleeping, by simple illusions. And stopping on this thought, I can clearly see that there are not any conclusive indices nor certain enough signs to clearly distinguish being awake from being asleep, so much so that I am amazed and my amazement is almost enough to persuade me to believe that I am sleeping."


A few years later, in 1635, Pedro Calderón de la Barca (1600-1681) a Spanish dramatist and religious philosopher, wrote a theatrical piece entitled "Life is a Dream".

This drama tells the story of an imaginary town in which Basilio, the king and famous astrologer, while creating the horoscope for the birth of his son Sigismondo, foresees that when he will take the throne he will become a bloodthirsty tyrant.

To stop this prophecy from coming true, he has the boy locked up in a tower for his entire life, his only contact with the world is through a servant who takes care of him. One day, the father, to test his son, drugs him to make him fall asleep and brings him to court. When the boy wakes up, his servant tells him the truth about his segregation.

Furious about the life that had been stolen from him, unused to being with other people, and dazed by all the people around him, he behaves in a superior, tyrannical and vindictive way.

He calms down only when he sees a girl, Rosaura, with whom he falls in love.

But the father, after seeing his son's reaction is truly convinced that he could turn into a tyrant, has him drugged again and taken back to the tower.

Once he woke up in his prison, Sigismondo thinks he dreamt about his visit to the court, but those images seem too real to him, and he begins to be confused between dreams and reality. To try and give his life some certainty, Sigismondo finally convinces himself about a superior truth: "life is but a dream ". The opera finishes with the rebellion of the people when they hear the news that the king does not want to nominate Sigismondo for the throne, but another prince instead.

The people cry out in favour of Sigismondo, they free him from the tower and call him the king. While Sigismondo is brought to the court, he meets Rosaura. Sigismondo is confused because he realises that he has already seen that girl and wonders whether it was in a dream or not. He accepts that confusion and takes the reins of power with justice and wisdom.

But is it a dream or reality ?