Pope Francis' articulation of the principle is found in the Apostolic Exhortation Evangelii Gaudium nn.231-233 (but see my comment below about the English of the first sentence of n.232):
Realities are more important than ideas
231. There also exists a constant tension between ideas and realities. Realities simply are, whereas ideas are worked out. There has to be continuous dialogue between the two, lest ideas become detached from realities. It is dangerous to dwell in the realm of words alone, of images and rhetoric. So a third principle comes into play: realities are greater than ideas. This calls for rejecting the various means of masking reality: angelic forms of purity, dictatorships of relativism, empty rhetoric, objectives more ideal than real, brands of ahistorical fundamentalism, ethical systems bereft of kindness, intellectual discourse bereft of wisdom.
232. Ideas – conceptual elaborations – are at the service of communication, understanding, and praxis. Ideas disconnected from realities give rise to ineffectual forms of idealism and nominalism, capable at most of classifying and defining, but certainly not calling to action. What calls us to action are realities illuminated by reason. Formal nominalism has to give way to harmonious objectivity. Otherwise, the truth is manipulated, cosmetics take the place of real care for our bodies. We have politicians – and even religious leaders – who wonder why people do not understand and follow them, since their proposals are so clear and logical. Perhaps it is because they are stuck in the realm of pure ideas and end up reducing politics or faith to rhetoric. Others have left simplicity behind and have imported a rationality foreign to most people.
233. Realities are greater than ideas. This principle has to do with incarnation of the word and its being put into practice: “By this you know the Spirit of God: every spirit that confesses that Jesus Christ is come in the flesh is from God” (1 Jn 4:2). The principle of reality, of a word already made flesh and constantly striving to take flesh anew, is essential to evangelization. It helps us to see that the Church’s history is a history of salvation, to be mindful of those saints who inculturated the Gospel in the life of our peoples and to reap the fruits of the Church’s rich bimillennial tradition, without pretending to come up with a system of thought detached from this treasury, as if we wanted to reinvent the Gospel. At the same time, this principle impels us to put the word into practice, to perform works of justice and charity which make that word fruitful. Not to put the word into practice, not to make it reality, is to build on sand, to remain in the realm of pure ideas and to end up in a lifeless and unfruitful self-centredness and Gnosticism.Even a cursory reading of this passage, written in the context of an exhortation whose subject is the new evangelisation, indicates Pope Francis' concern that ideas and realities should be aligned with each other, and not that ideas should he superceded by realities:
.....Ideas disconnected from realities give rise to ineffectual forms of idealism and nominalism, capable at most of classifying and defining, but certainly not calling to action. What calls us to action are realities illuminated by reason.....And the most fundamental reality is that of the Incarnation of the Word:
.... The principle of reality, of a word already made flesh and constantly striving to take flesh anew, is essential to evangelization....[The first two chapters of Luigi Giussani's foundational text, The Religious Sense (and remember that Pope Francis, as Cardinal Bergoglio presented the Spanish translation of this book at its launch in Argentina, and acknowledges his debt to the movement Communion and Liberation) are instructive background reading to this passage in Evangelii Gaudium. They are entitled "The First Premise: Realism" and "The Second Premise: Reasonableness".]
The English of the first sentence of Evangelii Gaudium n.232 as published on the Vatican website does not appear to be the same as the French and Italian (nor, so far as I can tell, of the Spanish and Portuguese), which would be more carefully translated into English as "The idea - the conceptual elaborations - is a function of the grasping/perception, of the understanding and of the conduct/operation of the reality":
232. Ideas – conceptual elaborations – are at the service of communication, understanding, and praxis.
232. L’idée – les élaborations conceptuelles – est fonction de la perception, de la compréhension et de la conduite de la réalité.
232. L’idea – le elaborazioni concettuali – è in funzione del cogliere, comprendere e dirigere la realtà.The non-English languages seem to better express the alignment of ideas to reality that is the intent of this section of Evangelii Gaudium. Likewise in this paragraph, what appears in English as referring to "what calls us to action" appears in the French and Italian as "what engages us" ... the sense being not dissimilar, though perhaps appearing more idiomatically correct.
In the light of the above, I was struck by the first of the answers in Pope Benedict's recently published interview. This seemed to express exactly the balance of "reality" and "idea" that Pope Francis has presented in Evangelii Gaudium and which Luigi Giussani offers in the first two chapters of The Religious Sense. It also strikingly includes a similar assertion of the necessity of the encounter with the community of the Church as part of the reality of faith as does n.233 of Evangelii Gaudium:
....faith is a profoundly personal contact with God, which touches me in my innermost being and places me in front of the living God in absolute immediacy in such a way that I can speak with Him, love Him and enter into communion with Him. But at the same time this reality which is so fundamentally personal also has inseparably to do with the community. It is an essential part of faith that I be introduced into the “we” of the sons and daughters of God, into the pilgrim community of brothers and sisters. The encounter with God means also, at the same time, that I myself become open, torn from my closed solitude and received into the living community of the Church. ....
.... Faith is not a product of reflection nor is it even an attempt to penetrate the depths of my own being. Both of these things may be present, but they remain insufficient without the “listening” through which God, from without, from a story He himself created, challenges me. In order for me to believe, I need witnesses who have met God and make Him accessible to me. In my article on baptism I spoke of the double transcendence of the community, in this way causing to emerge once again an important element: the faith community does not create itself. It is not an assembly of men who have some ideas in common and who decide to work for the spread of such ideas. Then everything would be based on its own decision and, in the final analysis, on the majority vote principle, which is, in the end it would be based on human opinion. ....