When used in the plural, metaphysics are the first principles of a science. Because Descartes errors are metaphysical errors in both senses, let s go back over some basics.
Science is a combined effort of the senses and the intelligence.
Intellectual knowledge comes from the senses. An example would be motion. The concept of motion and the measurement of motion are purely intelligible, not sensible. When we say that the intelligence penetrates into the being we are speaking of being as essence . Essence is only intelligible, not sensible.