What were members of a Roman Catholic religious order who took the same vows as a monk but traveled about preaching instead of living in monasteries?

Answer 1

They are known as "friars":

The Dominican Order, also called the Friars Preachers, was founded in 1215 by Dominic de Guzmán (c. 1170 - 1221), a native of Caleruega in Spain, who, to conform himself more closely to Christ Our Lord, used to remove his footwear and walked barefoot over the roads as he travelled preaching the Gospel.

The heresy which he was reforming was called Albigensianism. This was the revival of a heresy the Church saw many centuries earlier called Manichaeism. The Albigensians held to a dualistic philosophy which taught, among other things, that created objects and matter, such as the human body, were bad. This teaching, among others, was often considered a representation of what Catholics believed, so the Church sought to correct the misrepresentation. Many examples of the goodness of creation can be found throughout Sacred Scripture, particularly God's multiple proclamations of the goodness of His creation in Genesis 1, culminating in the first story of creation with man and woman who are made in God's image and likeness.

There have been many famous Dominicans after St. Dominic, but perhaps the most well-known Dominican in Catholic history is St. Thomas Aquinas. His writings have been influential in forming Catholic thought over the centuries, and are required reading for all seminarians studying for the priesthood. Among his more famous works are the Summa Theologica and the Summa Contra Gentiles.

Source Encyclopedia Americana Online (1918 edition - copyright expired and work in the public domain).

Answer 2

friars