"This Life's dim windows of the soul
Distorts the Heavens from Pole to Pole,
And leads you to believe a lie
When you see with, not through, the eye."
Eastern Orthodox Christians speak of man's spiritual eye as the 'nous.' This essay from the New Liturgical Movement blog goes into detail on the "eye of the heart;" and how trinitarian anthropology became skewed when, contra the Apostle Paul, we began to equate soul and spirit.
(There is a cantankerous streak in man that always wants to "improve" things by knocking off a portion of any three-legged stool...)
One of the links mentioned in the essay is to a piece by Stratford Caldecott -- which is, in part, a call to steer between the rock of Rationalism and the whirlpool of Romanticism. Here is his comment on contraception:
"The sexual relationship, for example, if it is not open to new life, collapses into a form of narcissism. Connected with this is a strong sense of what is wrong with the act of contraception. To contracept is wrong because by acting against the being of the child who might otherwise come to exist through the act; it turns the relationship back into a dualistic one, no longer 'asymmetrical' and no longer open to a mysterious 'third person.' It is to act (however unknowingly) not just against the potential child but against the presence within the marriage of the Holy Spirit, who is the Giver of Life."
Mr. Caldecott on how we got in this pickle:
"Rationalism cannot be overcome by mere intensity of sentiment. Romanticism cannot be overcome by more careful planning and calculation. We are caught in the dichotomy characteristic of Western thought since Descartes: the radical division between cold objectivity ('clear and distinct ideas') and unintelligent subjectivity. According to Christian 'non-dualism', if two realities are to be united without losing their distinctiveness, they must find their unity in a third. If this is applied not to the relationship between persons, but to the human faculties within the individual, it suggests that reason and intuition, thought and feeling, may find their unity and fulfilment in a third faculty, the 'intelligence of the heart'... "
[The papal encyclical reaffirming the ban on artificial birth control, 'Humanae Vitae,' was published in the summer of 1968. In January of that pivotal year, Malcolm Muggeridge resigned his rectorship of Edinburgh University in protest of the campus health center's decision to dispense contraceptive pills. A decade and a half later, Muggeridge and his wife joined the Catholic Church.]