The discussion centers on the nature of the natural logarithm function, specifically why ln(k) is considered a complex number when k is a positive integer. Participants explain that while k is positive, the logarithm can yield complex results due to its definition in the complex plane, particularly involving the Euler's formula. The argument highlights that ln(k) can be expressed as ln(k) + 2πi*n, where n is any integer, indicating the multi-valued nature of logarithms in complex analysis. Clarifications are made regarding the principal value of the logarithm, which is real for positive k but can extend into the complex realm. The conversation emphasizes the importance of understanding logarithmic functions in both real and complex contexts.