  The original concept of self-organized criticality (Bak et al.~1987), applied
to solar flare statistics (Lu and Hamilton 1991), assumed a slow-driven and
stationary flaring rate, which warrants time scale separation (between flare
durations and inter-flare waiting times), it reproduces power-law distributions
for flare peak fluxes and durations, but predicts an exponential waiting time
distribution. In contrast to these classical assumptions we observe: (i)
multiple energy dissipation episodes during most flares, (ii) violation of the
principle of time scale separation, (iii) a fast-driven and non-stationary
flaring rate, (iv) a power law distribution for waiting times $\Delta t$, with
a slope of $\alpha_{\Delta t} \approx 2.0$, as predicted from the universal
reciprocality between mean flaring rates and mean waiting times; and (v) pulses
with rise times and decay times of the dissipated magnetic free energy on time
scales of $12\pm6$ min, up to 13 times in long-duration ($\lapprox 4$ hrs)
flares. These results are inconsistent with coronal long-term energy storage
(Rosner and Vaiana 1978), but require photospheric-chromospheric current
injections into the corona.
