Schism, from a gnostic point of view, is essentially internal, i.e. psychological, a spiritual discord. From a gnostic point of view, schism may be made manifest in external separation, but in such cases that external separation is a mere *manifestation* of the schism, not the schism itself, which is internal. Hence, from the gnostic point of view, in the event of "external", visible or institutional divisions and separations where there is no internal malice or hatred or animosity, and the separating parties both desire the well-being of the other parties, the resulting divisions are not schisms. From the gnostic point of view, the unity is retained and preserved, because from the gnostic point of view unity is (essentially) spiritual, i.e. internal.
To see that such a view is gnostic, apply it to marriage. As long as the husband and wife separate amicably and without any animosity or 'loss of love', and wish the other spouse well, it is not a schism. The really important thing is that they continue to 'love each other' in their hearts, no matter whether they live in separate cities and/or take on paramours. "I don't love you any less; I simply want to live on my own, and try out other partners" is the growing gnostic lie in our culture's conception of spousal love. (See my "Sex, Dualism, and Ecclesial Unity".)
When 'schism' is defined as "a breach of charity", and 'charity' is understood in this gnostic way, then the formation of the various denominations is not considered to be schism, so long as the various separating parties wished each other well in the process of separation. That is how someone could recently say to me (with all sincerity) that the 44 Reformed denominations in the US are not schisms because in the historical separations of these denominations from each other, there was no "breach of charity".
Schisms *do* necessarily involve a breach of charity, but a breach of charity *properly understood*, not the gnostic conception of charity. There is necessarily a breach of charity between spouses who separate and don't wish or seek to be together any more, even if they have no animosity or dislike toward each other, and even if they continue to wish each other well. Charity is by its very nature unitive; and humans are essentially embodied beings. Therefore charity among humans necessarily and essentially involves the pursuit of embodied unity, not merely spiritual (internal) unity. We seek to be physically with those we love, sharing a table, a celebration, an evening, an event, a walk, a book, a film, etc. Charity among *human beings* seeks unified *embodied* communal life with the beloved. Charity in a human context necessarily seeks to be, in some sense, one body, not merely one spirit. (Eph 4:4) And that is why dividing into 44 denominations (i.e. 44 bodies) *is* a breach of charity, even if there were only smiles and good feelings and well-wishing throughout the process.
In order to heal our schisms, we must first recognize them for what they are. And in order to do that, we need to see charity for what it truly is, and that requires abandoning the gnosticism that now pervades our culture.
Lord Jesus, please unite us truly to Yourself, and to each other.
"Let unity, the greatest good of all goods, be your preoccupation." - St. Ignatius of Antioch (Letter to St. Polycarp)