Thinking about what makes science science can help people develop both an understanding of and a critical attitude towards knowledge. In this case study we explore how children participating in informal science communication activities can think about science by engaging in philosophical dialogues. The dialogue facilitator's inquisitive stance helps children develop arguments about knowledge, scientists, and science. The use of philosophical questions and a cover story involving alien scientists enthuses most children, but some find it frustrating. However, frustration acts as a motivator enhancing further reflection. Introducing this approach at science museums or science festivals challenges science communicators to question rather than to answer.