Final answer:
Mr. Gradgrind would justify his support of Lewis's marriage to Bounderby by highlighting the importance of marriage in society and the benefits it brings.
Step-by-step explanation:
Mr. Gradgrind would likely support Lewis's marriage to Bounderby by highlighting the institution of marriage and its importance in society.
He could argue that marriage is a noble institution and the foundation of society, pointing out that it is not good for man to be alone.
Mr. Gradgrind might also emphasize the benefits of companionship and partnership in marriage, highlighting how a strong marriage can provide support, happiness, and shared experiences.
He could use examples from the text, such as Old Grannis's excitement about being best man in the wedding, to illustrate the positive aspects of marriage.