Sri Aurobindo
Letters of Sri Aurobindo
Volume IV - Part 3
It is the entire inner rejection of the sex-pulls and vital pulls that is necessary, a rejection by the whole lower vital itself – the 
outer rejection can only be effective if this inner rejection comes to reinforce it. Usually people adopt the outer rejection because otherwise (if these things are indulged) the inner rejection is not likely to come since the vital trend is always being confirmed by the outer action – but if the outer is rejected, then the conflict is confined to the internal desire and fought out there. Naturally an outer renunciation by itself does not liberate.