An important aim of teaching philosophy in Dutch secondary schools is to learn about philosophy (that is, the great philosophers) by doing philosophy. In an earlier study published in PLoS ONE, we focused on the relationship between student learning activities and teacher behavior by analyzing eight lessons. Correspondence analysis revealed that doing philosophy was more effective in some lessons than in others. We replicated this finding in the current study, using 10 new lessons, and elaborated on the relationship between the likely causes for doing philosophy effectively. The data suggest that conducting a dialogue in the form of a philosophical discussion is sufficient for achieving an effective lesson, whereas the teachers’ guidance being shared with the students is a necessary but not sufficient condition for achieving an effective lesson.