Even according to your brother's theories, the emotion of love is capable of powerful attraction.

Cannot I hope that my passion--so strong, so great, so true, Zara!--will, with patience, draw you, star of my life, closer and closer, till I at last call you mine ?" I heard the faint rustle of Zara's silk robe, as though she were moving farther from him.
"You speak ignorantly, Prince.

Your studies with Casimir appear to have brought you little knowledge.

Attraction! How can you attract what is not in your sphere?
As well ask for the Moons of Jupiter or the Ring of Saturn! The laws of attraction and repulsion, Prince Ivan, are fixed by a higher authority than yours, and you are as powerless to alter or abate them by one iota, as a child is powerless to repel the advancing waves of the sea." Prince Ivan spoke again, and his voice quivered, with suppressed anger.
"You may talk as you will, beautiful Zara; but you shall never persuade me against my reason.

I am no dreamer; no speculator in aerial nothings; no clever charlatan like Casimir, who, because he is able to magnetize a dog, pretends to the same authority over human beings, and dares to risk the health, perhaps the very sanity, of his own sister, and that of the unfortunate young musician whom he has inveigled in here, all for the sake of proving his dangerous, almost diabolical, experiments.