Final answer:
Desiderius Erasmus valued inward religious feeling over external religious practices because he believed it brought about personal transformation and deeper piety, championing the idea of religio animi.
Step-by-step explanation:
Desiderius Erasmus, a northern Renaissance humanist, stressed that inward religious feeling was more important than external forms of religion because it led to a personal transformation and a more profound sense of piety. Erasmus advocated for a focus on inner spirituality over outer religious observances such as pilgrimages or fasting. This encouraged individuals to live their lives as better Christians, thereby reformation of the church would follow from personal change, rather than institutional mandates. This idea is consistent with the concept of religio animi, or the religion of the soul, which emphasizes the internal beliefs and feelings as the essence of truly authentic religious experience.