DescriptionI argue in this paper that Daniel Defoe’s Col. Jack (1722) is a well-knit sentimental novel that shows the real eighteenth-century London where rampant poverty and destitution has rendered a large number of people to be criminals. To get a complete picture of sentimentalism in Col. Jack, I have taken a brief survey of the views of critics about Defoe and his work, social history of London and the time within which Col. Jack is placed. I also argue about secularism and sentimentalism in the novel, Col. Jack’s sentimentalism in the light of psychoanalytical theory, and Defoe’s realism and sentimentalism in Col. Jack. The discussion on ‘secularism and sentimentalism’ is not a critique of Defoe’s religious belief. Col. Jack is a fictional work in the form of a biographical sketch of a rogue struggling with sin-virtue lifestyle; and Defoe portrays just that. Applying psychoanalytical approach to look at the sentimentalism in Col. Jack, we find Freudian pleasure and reality principles and the phenomenon of Oedipus complex at work. The realism and sentimentalism in Col. Jack combine to provide complete picture of destitution and its effects, the necessity of reasoning and its effects, compassion and its effects, and the importance of consistent effort to change extenuating circumstances to make life useful for self and for others -- hallmark of sentimentalism. Col. Jack is all about this, and a well-reasoned sentimental commentary on the societal incongruities that either make a man a sinful creature for none of his fault, or provide opportunity to a man to be a vitreous, useful gentleman.