In connection with this decree of the Council it may be seen how out of harmony with the spirit and practice of the Church is the cult of the "sacred heart of Jesus" which has been introduced into the Roman Catholic Church. Although the above-cited decree of the Fifth Ecumenical Council touches only on the separate worship of the Divinity and the Humanity of the Saviour, it still indirectly tells us that in general the veneration and worship of Christ should be directed to Him as a whole and not to parts of His Being; it must be one. Even if by "heart" we should understand the Saviour’s love itself, still neither in the Old Testament nor in the New was there ever a custom to worship separately the love of God, or His wisdom, His creative or providential power, or His sanctity. All the more must one say this concerning the parts of His bodily nature. There is something unnatural in the separation of the heart from the general bodily nature of the Lord for the purpose of prayer, contrition and worship before Him. Even in the ordinary relationships of life, no matter how much a man might be attached to another — for example, a mother to a child — he would never refer his attachment to the heart of the beloved person, but will refer it to the given person as a whole.
- Protopresbyter Michael PomazanskyOrthodox Dogmatic Theology, On the Latin cult of the "Heart of Jesus."