One characteristic of Calasanz that is not well known is that he felt intuition that in every culture, the schools could be the key that would open the door to the missionaries in both Protestant and non-Christian territories. And he was right.

He not only sent Religious to Protestant cities in Central Europe, bet he also wanted to go there himself. as he wrote to the Cardinal of Nikolsburg,

"Be certain that I will not cease doing what i can to send Piarist priests. In a short time, I hope to send you more, among whom I would really like to count myself."

In this same letter, Calasanz expressed the necessity of sending priests from their own countries.

"If vocations sprout from the country, it would be much better, since we find it very difficult to send priests, because of the great distance of the country and the difficulty of the language."

He even gave permission to one companion, the restless Fr. Mechor Alacchi, to found missions in the Orient.