What exactly is your self-esteem a ratio of?
What it argues
James splits the self into the I, the thinker, and the Me, what is thought about: material, social, and spiritual. Self-esteem he defines as success divided by pretensions, so it can be raised by achievement or lowered by ambition. The formula makes self-regard a ratio you can inspect rather than a mood you endure.
The probe
Write your current pretensions in your work, then your actual success at them. Compute the ratio honestly; then change one term deliberately.
The source
The Principles of Psychology, ch. X — William James, 1890. The link goes to the text or to a catalogue record for it, not to a summary. This one is the text itself.