This paper revisits the admixture of secular and spiritual aspects in Bildung. It aims at re-examining the intimate relations between the secular, rational and enlightened educational ideals, which were invested in the formation of the Bildung concept at the turn of the eighteenth century, and the religious, and mystical foundations of these ideals. The paper argues that Bildung should be regarded as a symbol of the unvarying presence of what sociologist Philip Wexler termed 'mystical interactions', that is, the manner in which mysticism becomes a resource for understanding the secular-modern (rational) education. Rather than holding to a simple differentiation between rational, enlightened education and religiosity, the paper points to the entwining of reason and faith in Bildung. The importance of revisiting the mystical aspect of a secular and rational educational ideal may rest in suggesting that such an ideal cannot be exhausted by a one-dimensional educational standpoint.