The European Solar Telescope (EST) is being designed to optimize studies of the magnetic coupling between the lower layers of the solar atmosphere (the photosphere and chromosphere) in order to investigate the origins and evolution of the solar magnetic field and its role in driving solar activity. In order to achieve this, the thermal, dynamic and magnetic properties of the solar plasma must be probed over many scale heights and at intrinsic scales, requiring the use of multi wavelength spectroscopy and spectropolarimetry at high spatial, spectral and temporal resolution. In this paper we describe some of the over-arching science questions that EST will address and briefly outline the main features of the proposed telescope design and the associated instrumentation package.