St. Thomas attempts to remove the difficulty of a sensuous thing producing a creative effect, by distinguishing between the "causa principalis et instrumentalis". God, as the principal cause, works through the sensuous thing as the means ordained by him for his end. "Just as instrumental power is acquired by the instrument from this, that it is moved by the principal agent, so also the sacrament obtains spiritual power from the benediction of Christ and the application of the minister to the use of the sacrament. There is spiritual power in the sacraments in so far as they have been ordained by God for a spiritual effect." This spiritual power remains in the sensuous thing until it has attained its purpose. At the same time, St. Thomas distinguished the "gratia sacramentalis" from the "gratia virtutum et donorum", in that the former perfects the general essence and the powers of the soul, whilst the latter in particular brings to pass necessary spiritual effects for the Christian life. Later, this distinction was ignored.