The foregoing statement finds confirmation in the words of the learned physiologist, Claude Bernard. " The sentiments we experience," he says, " are always accompanied by some reflex action of the heart, . . . and the impression of such sentiments creates a continuous exchange of influences between the heart and the brain." From the exchange of these influences Muzzarelli infers that there is a mutual interrelation between the love of the soul and the physical heart.
Without dwelling on this point any longer, it may be concluded that, physiologically speaking, the connection between the heart and the emotions is sufficiently close to authorize the statement that the heart is an indirect organ of the appetitive faculties. As such it participates in all the emotions, whereof none is stronger than love. The heart being thus conceived, it may be said that the Heart of Jesus is an organ united to the appetitive faculty of His human nature. In this sense it is the partial seat, organ and instrumental cause of all the acts and affection, and of all the virtues of our divine Lord. Hence, it is a partial seat, organ and instrument of the love of Christ.
To summarize all that can be said on this subject, it may be maintained that all physiologists admit an influence exercised on the heart by the affections and passions of man. It is likewise true, therefore, that the heart being thus acted upon, by reacting, participates actively in the affections of the soul. In other words, it is an established physiological principle that extrinsic impressions influence the heart intrinsically, and cause a reaction in it.