Solar filaments are discussed in terms of two contrasting paradigms. The st
andard paradigm is that filaments are formed by condensation of coronal pla
sma into magnetic fields that are twisted or dimpled as a consequence of mo
tions of the fields' sources in the photosphere. According to a new paradig
m, filaments form in rising, twisted flux ropes and are a necessary interme
diate stage in the transfer to interplanetary space of dynamo-generated mag
netic flux. It is argued that the accumulation of magnetic helicity in fila
ments and their coronal surroundings leads to filament eruptions and corona
l mass ejections. These ejections relieve the Sun of the flux generated by
the dynamo and make way for the flux of the next cycle.