Many students of Christian Science have found helpful comparisons in mathematics, that exact science to which De Quincey referred as having "not a foot to stand upon which is not purely metaphysical." In the Science of Christianity, as in the science of numbers, positive and negative are never blurred, the rules are invariable, explicit, and eternally demonstrable.
Few problems would be solved by a mathematician who said: "I have learned to add. Addition is wonderful; it is so satisfying, I am sure addition is enough." He would find that he also needed to know how to subtract, to multiply, and to divide. Similarly, the Christian Scientist will learn that he cannot confine his successful unfoldment to any one aspect of Christian Science, vital to the whole as that one aspect may be. The healing power of divine Love, God, will be manifested in the degree that this power is seen to include the might of Spirit, the wisdom of Mind, the beauty of Soul, the integrity of Truth, the permanence of Life, and the authority and exactness of undeviating Principle.
Likewise, confining treatment in Christian Science to absolute declarations of Truth may not always be wise. Sometimes vigorous denials of errors both general and specific may be needed to clear our thinking of error's debris. In "The First Church of Christ, Scientist, and Miscellany" Mary Baker Eddy writes (p. 235): "The tender mother, guided by love, faithful to her instincts, and adhering to the imperative rules of Science, asks herself: Can I teach my child the correct numeration of numbers and never name a cipher? Knowing that she cannot do this in mathematics, she should know that it cannot be done in metaphysics, and so she should definitely name the error, uncover it, and teach truth scientifically."
