The Science of Getting Rich opens with a declaration that poverty is not noble and that the fullest expression of human life, physical, mental, and spiritual, requires money. Wattles frames the desire to become rich not as greed but as the natural impulse of life seeking to expand. The book then makes its central claim: wealth is the result of doing things in a certain way, and that way is learnable by anyone.
The cosmological foundation Wattles lays is monistic. There is one original Formless Substance from which all things are made, and this substance is intelligent. It thinks, and when it thinks a form, it produces that form. Human beings are thinking centers within this substance, capable of originating thought and, by impressing vivid mental images upon Formless Substance, of causing the things they picture to be created through the ordinary channels of commerce and human activity.
A recurring distinction runs through the book between the competitive mind and the creative mind. The competitive mind works within a fixed supply, trying to get more than others; such gains are unstable and come at others' expense. The creative mind recognizes that supply is unlimited and that the goal is to add value: to give every person more in use value than one takes in cash value. This orientation keeps the thinker aligned with the creative intelligence of the universe rather than opposing it.
Gratitude is treated as a practical mechanism, not a pious sentiment. It keeps the mind fixed on abundance rather than lack, prevents the drift into competitive thought, and strengthens faith by maintaining the sense that good things are already moving toward the person. Wattles pairs this with precise instruction on forming a clear and definite mental picture of what one wants, holding it with steady purpose and unwavering faith, and mentally claiming possession of it as if it were already real.
The final movement of the book insists that thought without action is sterile. A person must act in their present business and present environment, doing all that can be done each day and doing each act with full efficiency. The crucial principle of efficient action is that it is not the quantity of acts but the quality of each one that advances a person. Every act performed with faith and purpose behind the mental image is a success in itself, and successes compound: each one opens the way to the next, drawing what is wanted toward the actor with increasing speed.