Thoughts Are Things presents Prentice Mulford's early formulation of mental causation and the shaping influence of thought upon character and circumstance. In this influential collection of essays, Mulford advances the proposition that thought is not passive reflection but active force. Habits of mind, he argues, shape disposition, opportunity, and outward condition. Written in a direct and conversational style, the work blends metaphysical speculation with practical observation, anticipating themes that would later define the New Thought movement. Emerging in the late nineteenth century, Mulford's writings contributed significantly to the development of modern self-culture philosophy. His emphasis on disciplined attention, inward clarity, and constructive expectation would influence later authors such as Ralph Waldo Trine and other early twentieth-century metaphysical writers. Presented here in its complete form, Thoughts Are Things remains an important document in the history of American spiritual and philosophical thought.