D. Teodósio was a very gifted young man. He knew Greek and Latin, was keen on philosophy and well respected amongst the great intellectuals of the time.
The Prince had a great interest in Astrology. He had a collection of charts of his family and made predictions on several political subjects. His astrological interests were encouraged and aided by his tutor, the Jesuit priest
António Vieira. Under the tutelage of astrologers of the day, he composed many astrological charts.