1. Introduction to the electron liquid 2. The Hartree-Fock approximation 3. Linear response theory 4. Linear response of independent electrons 5. Linear response of an interacting electron liquid 6. The perturbative calculation of linear response functions 7. Density functional theory 8. The normal Fermi liquid 9. The one-dimensional electron gas and the Luttinger liquid 10. The two-dimensional electron gas at high magnetic field.