  A unified approach to quintessence and inflation is investigated with the use
of a single scalar field. It is argued that successful potentials have to
approximate a combination of exponential and inverse power-law decline in the
limit of large values of the scalar field. A class of such potentials is
studied analytically and it is found that quintessential inflation is indeed
possible. Successful models, not involving more than two natural mass scales,
are obtained, which do not require fine-tuning of initial conditions and do not
result in eternal acceleration.
