  We propose a model that extends the binary ``united we stand, divided we
fall'' opinion dynamics of Sznajd-Weron to handle continuous and multi-state
discrete opinions. Disagreement dynamics are often ignored in continuous
extensions of the binary rules, so we make the most symmetric continuum
extension of the binary model that can treat the consequences of agreement
(debate) and disagreement (confrontation) within a population of agents. We use
the continuum extension as an opportunity to develop rules for persistence of
opinion (memory). Rules governing the propagation of centrist views are also
examined. Monte Carlo simulations are carried out. We find that both memory
effects and the type of centrist significantly modify the variance of average
opinions in the large timescale limits of the models. Finally, we describe the
limit of applicability for Sznajd-Weron's model of binary opinions as the
continuum limit is approached. By comparing Monte Carlo results and long
time-step limits, we find that the opinion dynamics of binary models are
significantly different to those where agents are permitted more than 3
opinions.
