The great rule for preventing the increase and power of vicious habits is, watch against beginnings. Sin doth not attempt dominion but in particular instances, by one especial lust or another. Wherefore, if any sin or corrupt lust begin, as it were, to set up for a peculiar predominancy or interest in the mind and affections, if it be not entertained with severe mortification, it will ruin the peace, if not endanger the safety, of the soul.