How can one deal with a father who does not care for the psychological and spiritual well-being of his children, and refuses scientific discussion, which has led to one of his children deviating intellectually?

One must thank Allah for the blessing of guidance by diligently seeking beneficial knowledge and performing righteous deeds. Gratitude to Allah is expressed through the heart, tongue, and limbs. Part of showing gratitude is honoring one's parents, doing good to them, and warding off evil from them to the best of one's ability. When advising parents, the advice must be given gently, kindly, wisely, and with good admonition, avoiding harshness and roughness in speech, and without raising one's voice to them. If it is possible to seek the help of some people of knowledge and virtue to guide the father, that would be better. The guidance of hearts is not within your power; it is in the hands of Allah the Almighty. Always remember that he is your father, and you must adhere to good manners with him, use refined language, and recall the words of Allah the Almighty: "So do not say to them [anything that indicates] displeasure and do not reprimand them but speak to them a noble word."