If something is true, no matter who said it, it is always from the Holy Spirit.
About Thomas Aquinas
Thomas Aquinas ( ə-KWY-nəs; Italian: Tommaso d'Aquino, lit. 'Thomas of Aquino'; c. 1225 – 7 March 1274) was an Italian Dominican friar and priest, theologian, and philosopher. He is considered one of the most influential thinkers in the history of Catholic theology and Western philosophy. He is the father of a school of thought (encompassing both theology and philosophy) known as Thomism.